>I’m using Optimistic Row Buffering of my two relational tables in my Single Tier Application. Currently it is running perfectly on Network too. I’m facing only one problem when two users try to change a same record at same time the Error comes “Update Conflict”. How can it be remove in the current environment?

Have you taken a look at John's buffering article at
http://www.levelextreme.com/cgi-bin/xworks.exe?2,1,3,442

This might shed some light on the issue.