Code optimizer in c#,MSSQL

Hello dear,
I have point of sales software
-Need to check the code and optimize it if need
– convert function from C# to sql Server procedure or function .
– Need apply trigger on sql server when unknow problem happen like the data was not insert in table or update.
The software make in visual studio C# and Microsoft Sql server
Note : the Application in Arabic interface
the file below contain code of Pos interface