Thanks a lot off Bonnie Bernet for given valuable time
i will follow your suggestion
i am very happy to see you code as

Dim csql As String = ""
csql = [String].Format( _
      "insert into Employee_week_offdays (emp_unique_code,week_off_date,off_day) " + _
                 "values({0}, {1}, {2})", @emp_code, @mydate, @off_day)

'can i write this like
'mytable from dataset

Dim csql As String = ""
csql = [String].Format( _
      "insert into Employee_week_offdays (emp_unique_code,week_off_date,off_day) " + _
                 "values({0}, {1}, {2})", select emp_unique_code,week_off_date,off_day from mytable )