server validation: how to disallow quotes on filename?

Hello Ray,
I already applied the alphanumeric rule to a file field validation allowing only uppecases, lowercases, numbers and few charaters (_-.), excluding the parenthesis.
But the page crash while uploading a file containing a single quote. I already know this is a reserved characters, but it can happen that a a site visitor doesn't know this.
How can I solve this? I'm using DB1, at the moment.
I have DB2 but I can't migrate all live websites now.
TIA
tony

Please attach a copy of the page you are working on with the issue. I'll see if I can spot how to fix it in the code. Do you see an error? or does the page just go white?

Originally Said By: Ray Borduin

  Please attach a copy of the page you are working on with the issue. I'll see if I can spot how to fix it in the code. Do you see an error? or does the page just go white?  

Thanks Ray,
the page goes just blank.
I attached the page as private attachment.
In the meantime I solved asking the customer to check for quotes or double quotes in the filename.
Thanks, anyway.
Tony

A blank page usually means there is an error, but displaying error messages is turned off.

Put this on the top of the page:

<?php ini_set("display_errors",1); ?>

That might allow the error to display, and if you can tell me what the error is, then I might be able to better understand the issue. I think it is probably an issue with the file upload, not the validation.