1-One way to resolve this issue is to append empno as a query string against that link button as
lnkbtn. Postbackurl = "update.aspx?empno" + empno
in the GridView.
2-on the Update.aspx page get that parameter from Query string as
int empno = convert.toInt32(Request.QueryString["empno"]
3- pass that empno to the sql query or any other database ur using and got the desired result against that empno.