i am getting errorr that"input string was not in a correct format"
for ExecuteNonQuery()...
please some one help me...
here is my code
For i = 0 To a - 1

            SqlCmd = New SqlCommand("update_IRProfile", SqlCon)
            SqlCmd.CommandType = CommandType.StoredProcedure

            viewstate("g") = Request.Form("txta" & i).ToString()
            viewstate("g1") = Request.Form("txtb" & i).ToString()

            SqlCmd.Parameters.Add("@AAttr", SqlDbType.Char, 4).Value = lookup.SelectedItem.Text.ToString()
            SqlCmd.Parameters.Add("@VValue", SqlDbType.Int).Value = CStr(viewstate("g"))
            SqlCmd.Parameters.Add("@IValue", SqlDbType.Int).Value = CStr(viewstate("g1"))
            SqlCmd.Parameters.Add("@Desc", SqlDbType.VarChar, 25, "Descrp").Value = Label1.Text.ToString()

            SqlCmd.ExecuteNonQuery()
        Next i

Use a Try ... Catch block to get a more descriptive error
Response.write ex.Message

Also try to Response.Write SqlCmd.CommandText and don't execute it, this way you can see the sql string structure.