At arraignment th police report says that I was stopped for no seatbelt .I was charged with DWI he claims the oder of alcohol and glossy eyes. On the way out I stopped at traffic ticket office and there is no seatbelt ticket under my i.d Was that a lawful stop?
You can be arrested and taken to jail for a seatbelt violation so that is fair game for a traffic stop. A case from Texas actually went to the US Supreme Court on this issue in Atwater v. City of Lago Vista.
That said, your DWI attorney may be able to determine from the officer's DashCam video whether or not the officer really had an angle to notice the potential seatbelt violation before you were stopped.
The no seatbelt reason is the probable cause for stopping you. A police officer does not write the ticket for the no seatbelt because a DWI is a more serious crime. Nevertheless, a judge may find that the probable cause was not reasonable. Hopefully, you landed in a friendly Houston Harris County court. You have more than a fighting chance. Good luck to you!