Transaction Error - Critical Issue

Hi Friends,





We developed an application in the ASP.Net with C#.


We are going to do a task in the transaction.


It is working perfectly. But if two users comes simultaneously, then


It gives an exception that Transaction is already commited.





First transaction Commited Successfully.


When Second transaction goes to Commit()


Then it generate this error.


We are unable to find this problem Whether this is problom from SQL Server or DOTNET.





Pls give ur suggestions.





Thanks and waiting a helpful response.





Sachin