Inserting date values into SQL

If this isn't in the right subject forum, feel free to move it to a more appropriate one. This involves ASP and VB issues as well as SQL.<br><br>I'm trying to insert values from dropdown lists into a SQL Field who's data type is 'datetime'. Since the values from the lists are string, I've tried using Cdate to convert the data but I get an error when I do that:<br><br>System.InvalidCastException: Cast from string "" to type 'Date' is not valid.<br><br>Here's what I have in the code, server-side:<br><div class="msgQuoteWrap"><div class="msgCode"><br>Public Sub btnSave_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSave.Click<br> Dim dateInfo As New System.Globalization.DateTimeFormatInfo()<br> Dim MyMonth, MyMonth2, MyDay, MyDay2, MyYear, MyYear2 As Date<br> MyMonth = CDate(ddlMonth.SelectedItem.Value)<br> MyDay = CDate(ddlDay.SelectedItem.Value)<br> MyYear = CDate(ddlYear.SelectedItem.Value)<br> MyMonth2 = CDate(ddlMonth2.SelectedItem.Value)<br> MyDay2 = CDate(ddlDay2.SelectedItem.Value)<br> MyYear2 = CDate(ddlYear2.SelectedItem.Value)<br> If txtWhatObjectGetsFocus.Text = "lnkAdd" Then<br> 'adding record to umv_messages SQL table<br> Dim objSQLMsgInfo As New SQLComponent()<br> objSQLMsgInfo.strConnection = objConstants.DBConnectionString_Umove<br> objSQLMsgInfo.strSQL = "INSERT INTO umv_memoManagement (mgt_memoURL, mgt_memoDescription, mgt_forWhatGroup, mgt_forWhatMemberInGroup, mgt_effectiveStartDate, mgt_effectiveEndDate) _<br> VALUES ('" & lstMemos.SelectedItem.Text & "' , '" & txtDescrip.Text & "' , '" & ddlGroup.SelectedItem.Value & "' , '" & ddlMember.SelectedItem.Value & "' , '" & _<br> Trim(MyMonth) & "/" & Trim(MyDay) & "/" & Trim(MyYear) & "' , '" & Trim(MyMonth2) & "/" & Trim(MyDay2) & "/" & Trim(MyYear2) & "')"<br> objSQLMsgInfo.ExecuteSqlStatement()<br> 'indicating message was added<br> lblMessage.Text = "MESSAGE ADDED!"<br> Else<br> 'update the umv_message table indicating message has been read<br> Dim objSqlMessageUpdate As New SQLComponent()<br> objSqlMessageUpdate.strConnection = objConstants.DBConnectionString_Umove<br> objSqlMessageUpdate.strSQL = "UPDATE umv_memoManagement SET mgt_memoDescription = " & txtDescrip.Text & ", mgt_forWhatGroup = " & ddlGroup.SelectedItem.Value & ", mgt_forWhatMemberInGroup = " & ddlMember.SelectedItem.Value & _<br> ", mgt_effectiveStartDate = " & Trim(MyMonth) & "/" & Trim(MyDay) & "/" & Trim(MyYear) & ", mgt_effectiveEndDate = " & Trim(MyMonth2) & "/" & Trim(MyDay2) & "/" & Trim(MyYear2) & " WHERE mgt_memoURL = " & Trim(lstMemos.SelectedItem.Text)<br> objSqlMessageUpdate.ExecuteSqlStatement()<br> 'indicating message was updated<br> lblMessage.Text = "MESSAGE UPDATED!"<br> End If<br>End Sub</div></div><br><br>On the client-side for the Dropdown control "ddlMonth", I've given the alpha months numeric values. I had hoped this would ease the date-conversion process; apparently it hasn't worked.<br><br>Can anyone help? <img src="/forum/emoticons/confused.gif" alt="confused">