I'm trying to open various Excel files to determine which
ones are not in a valid format. I have the following
snippit of code:

Try
Dim bDisplayAlertsOldValue
Dim workBook As
Excel.Workbook
bDisplayAlertsOldValue =
m_excelApp.DisplayAlerts
m_excelApp.DisplayAlerts =
False
workBook =
m_excelApp.Workbooks.Open(fileName)
workBook.Close(False)
m_excelApp.DisplayAlerts =
bDisplayAlertsOldValue

Catch ex As Exception
MsgBox(ex.ToString())
End Try

The problem I'm encountering is this. If I don't disable
the DisplayAlerts property, then Excel prompts the user
with the standard file is in incorrect format dialog. My
application is going to run without user interaction over
many excel files. If I disable the DisplayAlerts property,
Excel no longer throws the exception that I was catching
after the dialog. Any ideas?

-Dan