In the
 United States Court of Appeals
              For the Seventh Circuit
                        ____________

No. 04-1401
PPM FINANCE, INCORPORATED, in its capacity
as agent for JACKSON NATIONAL LIFE
INSURANCE COMPANY,
                      Plaintiff-Counter-Defendant-Appellee,
                               v.


NORANDAL USA, INCORPORATED,
                    Defendant-Counter-Plaintiff-Appellant,
                               v.


PPM AMERICA SPECIAL INVESTMENTS CBO II, L.P.
and PPM AMERICA SPECIAL INVESTMENTS FUND, L.P.,
                               Counter-Defendants-Appellees.

                        ____________
        Appeal from the United States District Court for
       the Northern District of Illinois, Eastern Division.
            No. 02 C 7987—Amy J. St. Eve, Judge.
                        ____________
 ARGUED SEPTEMBER 15, 2004—DECIDED DECEMBER 16, 2004
                        ____________
2                                                No. 04-1401

    Before EVANS, WILLIAMS, and SYKES, Circuit Judges.
  EVANS, Circuit Judge. In this commercial dispute, one
creditor, Jackson National Life Insurance Company, sued
another, Norandal USA, Incorporated, demanding that
Norandal fork over a substantial sum of money it obtained
from a common debtor, who we will simply call Scottsboro.
The district court agreed with Jackson and granted its mo-
tion for summary judgment to the tune of $4.4 million, in-
cluding prejudgment interest. Aggrieved by this decision,
Norandal appeals.
  Norandal is a processor of aluminum products. In Febru-
ary of 1999, it agreed to sell its Alabama processing plant
to Scottsboro for approximately $92 million. To fund the
acquisition, Scottsboro secured $69 million from Jackson,
plus additional credit extensions. It got another $7.5 million
loan from PPM America Special Investments CBO II, L.P.
and PPM America Special Investments Fund, L.P. (col-
lectively PPM). To cover the remainder, Scottsboro executed
a promissory note to Norandal for $7.8 million. Thus,
Jackson, PPM, and Norandal all became Scottsboro cre-
ditors.
  To determine their relative rights, these creditors and
Scottsboro entered into a subordination agreement giving
Jackson a senior security interest in Scottsboro’s assets.
Under the agreement, Norandal was required to turn over
to Jackson any payments it received from Scottsboro while
Scottsboro was in default to Jackson. During negotiations,
Norandal requested a provision that would require Jackson
to notify Norandal of any defaults by Scottsboro. Jackson
refused.
  From October of 1999 through January of 2001, Scottsboro
defaulted on several obligations to Jackson. Despite these
defaults, Jackson continued to loan Scottsboro money, which
Scottsboro in turn used to make 15 scheduled payments to
Norandal. Jackson did not notify Norandal of Scottsboro’s
No. 04-1401                                                  3

defaults until July of 2001. Only days later, Jackson and
PPM filed involuntary petitions for relief in bankruptcy
against Scottsboro.
   In November of 2002, Jackson filed this suit against
Norandal to recover the money Norandal received from
Scottsboro. Jackson’s complaint alleged that Norandal
breached the subordination agreement by not turning over
the payments it received from Scottsboro at a time when
Scottsboro was in default to Jackson. In response, Norandal
filed three counterclaims, including one seeking a declara-
tory judgment that Jackson had no right to recover because
it had failed to give prompt notice that Scottsboro had
defaulted. We review the district court’s entry of summary
judgment to Jackson de novo, Fix v. Quantum Indus.
Partners LDC, 

, 552 (7th Cir. 2004). The same
standard of review applies to the district court’s interpreta-
tion of the subordination agreement, Bourke v. Dun &
Bradstreet Corp., 

, 1036 (7th Cir. 1998).
  This case presents rather straightforward questions of
contract interpretation. Under Illinois law, courts must as-
certain parties’ intentions exclusively from an agreement’s
language if it is clear and unambiguous. Kaplan v. Shure
Bros., Inc., 

, 604 (7th Cir. 2001); Air Safety,
Inc. v. Teachers Realty Corp., 

, 884 (Ill. 1999).
And if clear and unambiguous, one party’s particular in-
terpretation of its terms at the time of execution is immate-
rial. 

; Am. Nat’l Trust Co. of Chi. v.
Ky. Fried Chicken of S. Cal., Inc., 

, 211 (Ill.
App. Ct. 1999).
  Under the subordination agreement, Norandal could not
accept or retain payments from Scottsboro if Scottsboro was
in default to Jackson:
    2.3. Restriction on Payments. Notwithstanding any pro-
    vision of any Subordinated Debt Document to the
    contrary, no Obligor [Scottsboro] may make, and no
4                                               No. 04-1401

    Subordinated Creditor [Norandal] may receive, accept
    or retain any payment of principal, interest or any other
    amount with respect to the Subordinated Debt until the
    Senior Debt is paid in full . . . except that (I)
    [Scottsboro] may make and [Norandal] may receive
    scheduled payments of principal and interest . . . under
    the Subordinated Note on an unaccelerated basis so
    long as no Senior Default shall have occurred and be
    continuing or would result therefrom . . . .
The agreement further provides that Norandal must turn
over to Jackson any funds it received in violation of section
2.3:
    2.5. Incorrect Payments. If any payment or distribution
    on account of the Subordinated Debt not permitted to
    be made by any Obligor [Scottsboro] or received by any
    Subordinated Creditor [Norandal] under this Agreement
    is received by [Norandal] before all Senior Debt is paid
    in full in cash, such payment or distribution shall not
    be commingled with any asset of [Norandal], shall be
    held in trust by [Norandal] for the benefit of [Jackson]
    and shall be paid over to [Jackson], or [its] represen-
    tatives, for application on a pro rata basis . . . to the
    payment of the Senior Debt then remaining unpaid,
    until all of the Senior Debt is paid in full in cash.
  The district court concluded that this language is clear
and unambiguous and requires Norandal to disgorge the
money it received from Scottsboro. A contract provision is
ambiguous only if it is subject to more than one reasonable
interpretation. Commonwealth Ins. Co. v. Stone Container
Corp., 

, 778 (7th Cir. 2003); Lapham-Hickey
Steel Corp. v. Prot. Mut. Ins. Co., 

, 846 (Ill.
1995). Under section 2.5, note payments “not permitted to
be made by [Scottsboro] or received by [Norandal] under
this Agreement” “shall be paid over to [Jackson].” And
under section 2.3, payments are not permitted to be made
No. 04-1401                                                 5

if Scottsboro was in default to Jackson. These provisions are
unequivocal and susceptible to only one reasonable in-
terpretation—Norandal must remit to Jackson any money
it received from Scottsboro while Scottsboro was in default
to Jackson.
  Norandal argues that the subordination agreement is
ambiguous. Specifically, it claims that the payments made
by Scottsboro to Norandal must have been permitted under
section 2.3 because Jackson actually facilitated these pay-
ments by loaning Scottsboro more money. In support,
Norandal cites the testimony of John Krupinski, Scottsboro’s
former CFO, who testified that Jackson knowingly per-
mitted Scottsboro to make payments to Norandal despite it
being in default to Jackson. But Jackson’s post-default
loans had no bearing on the parties’ rights and obligations
under section 2.3. Indeed, section 3 of the agreement ex-
pressly allowed Jackson to increase the amount of Scottsboro’s
senior debt without affecting Norandal’s obligations under
the agreement.
  Norandal’s primary argument is that Jackson was re-
quired to notify it that Scottsboro was in default and that
Jackson’s failure to do so bars it from recovering the money
paid to Norandal. As the district court aptly noted, however,
nothing in the subordination agreement required Jackson
to notify Norandal of Scottsboro’s default. Indeed, Norandal
admits that it asked for a notice provision during contract
negotiations, a request that Jackson rebuffed.
  Faced with this situation, Norandal advances three argu-
ments, which we reject. First, it argues that the agreement’s
silence regarding notice is a “gap,” and that a notice re-
quirement should be read into it. We initially note that
Norandal forfeited this argument because it failed to make
it before the district court. E.g., Ocean Atl. Dev. Corp. v.
Aurora Christian Schs., Inc., 

, 1004 (7th Cir.
2003). Forfeiture notwithstanding, Norandal’s contention is
6                                                No. 04-1401

frivolous. As Jackson points out, a gap in a contract arises
when the contract does not account for unforeseen events.
See Dato v. Mascarello, 

, 183-84 (Ill. App. Ct.
1989). But here, Norandal sought a notice provision, failed,
and then entered into the subordination agreement anyway.
We know for a fact that the parties contemplated notice; its
omission from the agreement was no oversight. Norandal is
now seeking to rewrite the agreement to require notice, but
courts are not in the business of rewriting contracts to
appease a disgruntled party unhappy with the bargain it
struck. See Owens v. McDermott, Will & Emery, 

, 154 (Ill. App. Ct. 2000); Barille v. Sears Roebuck & Co.,

, 122 (Ill. App. Ct. 1997); Saunders v. Mich.
Ave. Nat’l Bank, 

, 610 (Ill. App. Ct. 1996).
  Norandal also argues that notice is required because “sen-
ior default notice” is included in the subordination agree-
ment’s definition section. But this definition provision did
not give Norandal the right to be notified because “senior
default notice” did not appear anywhere else in the agree-
ment. In contrast, the phrase “subordinated default notice”
is defined in the agreement but also appears in section 6,
which requires Norandal to notify Jackson if Scottsboro
defaults. Despite Norandal’s arguments to the contrary,
there simply is no provision in the agreement imposing a
reciprocal obligation.
  Norandal’s final argument on this point is that the
district court erred by failing to consider extrinsic evidence
showing that Jackson was required to provide notice under
the subordination agreement. But courts look to extrinsic
evidence to determine the parties’ intentions only if an
agreement is ambiguous, e.g., Air 

,
and as we have explained, this one is not. And in any event,
the extrinsic “evidence” cited by Norandal does not support
the interpretation it urges. Norandal points to the fact that
Jackson actually gave it written notice of default just prior
to Scottsboro’s bankruptcy as evidence that notice was re-
No. 04-1401                                                 7

quired. But just because Jackson ultimately notified Norandal
of Scottsboro’s default does not mean that its failure to do
so earlier forfeited its right to recover under the agreement.
  Norandal’s next attack is factual. It contends that the
district court erred by concluding that there is no genuine
issue of material fact as to whether Scottsboro defaulted.
Krupinski, aided by financial statements, testified that
Scottsboro failed to maintain the minimum debt service
coverage ratio, interest coverage ratio, and tangible net
worth ratio; made unauthorized capital expenditures; failed
to disclose certain inventory; and experienced a labor strike.
All of these events violated the subordination agreement. In
response to this evidence, Norandal advances only the
testimony of Jeff Podwika, a PPM loan officer who testified
that prior to December of 2000 he was “comfortable with
the situation” as to Scottsboro. He also testified generally
that when one of his accounts is in default, he typically
sends some form of communication informing the borrower
that it has defaulted. But this testimony was not specific
enough to refute the evidence supplied by Jackson. Notably,
Podwika did not specifically refute the testimony and
financial statements offered by Jackson establishing that
Scottsboro was in default nor did he say at any point that
Scottsboro was not in default. Norandal failed to offer spe-
cific, concrete evidence suggesting that Scottsboro was not
in default, which is fatal to its assertion that the case must
be resolved by a jury. Salvadori v. Franklin Sch. Dist., 

, 996 (7th Cir. 2002) (nonmovant must present de-
finite, competent evidence in rebuttal to defeat a summary
judgment motion).
  Norandal also argues that the district court erred in cre-
diting Krupinski’s testimony because he lacked personal
knowledge about whether Scottsboro defaulted. But that is
simply untrue. Krupinski directly participated in calcu-
lating the financial statements which demonstrated that
Scottsboro was in default. Moreover, Norandal does not
8                                                 No. 04-1401

identify which portions of Krupinski’s testimony fell outside
of his personal knowledge. And in any event, as Jackson
correctly points out, Krupinski was designated as a witness
under Fed. R. Civ. P. 30(b)(6), which authorized him to
testify not only to matters within his personal knowledge but
also to “matters known or reasonably available to the
organization.” See Pugh v. City of Attica, Ind., 

,
627 n.7 (7th Cir. 2001). Thus, Krupinski was free to testify
to matters outside his personal knowledge as long as they
were within the corporate rubric.
  Next, Norandal claims that Jackson waived its right to
recover by facilitating Scottsboro’s payments to Norandal.
In Illinois, “waiver” is a voluntary and intentional relin-
quishment of a known right. E.g., Chatham Corp. v. Dann
Ins., 

, 494 (Ill. App. Ct. 2004). Waiver may
be express through agreement or implied through conduct.
E.g., Ryder v. Bank of Hickory Hills, 

, 49 (Ill.
1991). Here, we agree with the district court’s conclusion
that Jackson did not waive its right to recover. In the first
instance, section 8 of the agreement required any waiver to
be in writing and signed by the parties. That never hap-
pened. Despite this, Norandal claims that Jackson’s post-
default loans constituted an implied waiver. “Waiver will be
implied when a party’s conduct is inconsistent with an
intention to assert the right.” 

loans
to Scottsboro were not inconsistent with its later efforts to
recoup that money pursuant to the agreement. Indeed,
section 3 explicitly authorized Jackson to make additional
loans without affecting Norandal’s obligations under the
agreement.
  Finally, Norandal objects to the district court’s award of
prejudgment interest, a decision we review for an abuse of
discretion. E.g., Ameritech Info. Sys., Inc. v. Bar Code
Resources, 

, 574 (7th Cir. 2003). The Illinois
Interest Act provides that a creditor shall be awarded
interest at the rate of 5% per year for all moneys after they
No. 04-1401                                                 9

become due on any “instrument of writing.” 815 ILCS 205/2
(2002); Sna Nut Co. v. Haagen-Dazs Co., 

, 734
(7th Cir. 2002). The purpose of granting prejudgment inter-
est is “to make a deprived plaintiff whole.” Jahn v.
Kinderman, 

, 122 (Ill. App. Ct. 2004) (citing
In re Estate of Wernick, 

, 887 (Ill. 1989)). To
demonstrate debt on an “instrument of writing,” a creditor
must establish three elements: (1) a written instrument that
establishes indebtedness; (2) a specific or inherent due date;
and (3) that the indebtedness is subject to easy calculation.
Adams v. Am. Int’l Group, Inc., 

, 30 (Ill. App.
Ct. 2003).
  All of these requirements were met here. Norandal claims
that the district court abused its discretion because the
subordination agreement did not specify a due date when
payments must be turned over. But under the plain terms
of the agreement, money became due once Norandal failed
to remit the payments it received from Scottsboro while
Scottsboro was in default to Jackson. Thus, the time of de-
fault is clear—the contract contains an inherent due date.
See Reserve Ins. Co. v. Gen. Ins. Co. of Am., 

,
940-42 (Ill. App. Ct. 1979) (recognizing time of default as an
“inherent” due date to trigger entitlement for prejudgment
interest). Norandal also argues that the agreement does not
establish a debtor-creditor relationship because Jackson did
not loan it money. But the Illinois Interest Act is not
confined to lending institutions; rather, it applies generally
to “creditors” on “instruments of writings.” See 815 ILCS
205/2 (2002); 

(rejecting similar
argument). The subordination agreement clearly placed
Norandal in the role of debtor vis-á-vis its senior creditor,
Jackson. And finally, Norandal’s claim that the amount
owed is not easily calculated is frivolous—Norandal received
15 equal payments totaling close to $3.8 million after
Scottsboro had defaulted. This sum is easily calculated.
10                                           No. 04-1401

 For these reasons, the judgment of the district court is
AFFIRMED.


A true Copy:
      Teste:

                      ________________________________
                      Clerk of the United States Court of
                        Appeals for the Seventh Circuit




                 USCA-02-C-0072—12-16-04