below code may help u dear....
GridViewRow row = (GridViewRow)GridView1.Rows[e.RowIndex];
Button btn = (Button)row.FindControl("Edit");
Label Id = (Label)row.FindControl("lbl_EmployeeId");
TextBox employeename = (TextBox)row.FindControl("txt_Ename");
TextBox Workstation = (TextBox)row.FindControl("txt_Workstation");
sq = "update Employee set Ename='+employeename & Workstation ='+Workstation where EmployeeID='+id";
SqlCommand cm = new SqlCommand(sq, con);
cm.ExecuteNonQuery();
bind();