A simplified version of my problem. Consider a single command button on a
blank worksheet. I want to be able execute the command button Click event
with both the Return key and a mouse click. I want to be able to clear the
message box with both the Return key and a mouse click. If I try to clear the
message box with the Return key, it also executes the command button Click
event again. So using the Return key to clear the message box puts you into
a loop. Any ideas are greatly appreciated.

Thanks, Tom

'In ThisWorkbook
Private Sub Workbook_Open()
Sheet1.Button1.Activate
End Sub

'In Sheet1
Private Sub Button1_KeyUp(ByVal KeyCode As MSForms.ReturnInteger, ByVal
Shift As Integer)
Select Case KeyCode
'Return is only key press that we care about
Case vbKeyReturn
Call Button1_Click
End Select
End Sub
Private Sub Button1_Click()
MsgBox "I am stuck in a loop when I use the Return key to clear this message
box" & vbNewLine & "but everything is fine if I use a mouse click to clear
this message box"
End Sub