Question : How can I return an error message when a field or control is Blank

Hi experts
I am currently designing an Access form that produces a purchase order, I have a button on the form which opens a report for printing.
I want to make the report refuse to open if the operator hasn't selected their name in the "ordered by" combo box the data source for that control is a value list (of names)
I would be grateful for any help as I have spent too long trying to code it already!
Access 2007

Answer : How can I return an error message when a field or control is Blank

Hello Tintoman51,

Put a snippet like this into the Click event sub for that button:

    If Nz(Me!OrderedBy, "") = "" Then
        MsgBox "You must select a name to order by", vbCritical, "Invalid Entry"
        Me.OrderedBy.SetFocus
        Exit Sub
    End If

Regards,

Patrick