File uploading

I have the standard set up for uploading files. It works fine, except when the customer clicks on the upload button but has forgotten to specify the file name in the text box. In this case it throws an error further down the script.

I tried inserting the following, but it doesn't work.

<code>
If (file1.PostedFile Is Nothing) Then
            Labelb.Text = "You need to enter something in the textbox"
            Labelc.Text = "Press the BROWSE button and click on one of the files"
            GoTo 888
        End If
</code>
It doesn't seem to think file1.PostedFile is "".
Something here I have misunderstood. Can someone assist, please ?



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