Here's another sample function you could use (and create something similar for dates and times) to make your life easier when putting SQL strings together...

 Function EnquoteString(strText As String) As String 
Enquote = "'" & strText & "'"
End Function
Which would be used like so...





 Sub MyComboBoxQueryRowSourceThingee() 
    Dim strFirstName As String 
    Dim datBirthDate As Date 
    Dim intFavoriteInteger As Integer 
    Dim strSQL As String 
    strFirstName = "Marco" 
    datBirthDate = #6/28/2005# 'Note this is American format: Month/Day/Year
    intFavoriteInteger = 19 
    strSQL = "SELECT peeps.strFirstName, peeps.strLastName, peeps.datBirthDate," _ 
    & " peeps.intFavoriteInteger FROM tblPeople AS peeps" _ 
    & " WHERE peeps.strFirstName=EnquoteString(strFirstName) _ 
    & " AND peeps.datBirthDate=#" & datBirthDate & "#" _ 
    & " AND peeps.intFavoriteInteger=" & intFavoriteInteger & ";" 
    Debug.Print strSQL 
End Sub

I find using functions like this improves readability, and more importantly, it reduces mistakes.