Alert for Upload control does not display

I have an element called ../EndorsementLogo/Data as a refrence to an Upload control
The element has an associated xsd entry that limits the size of the base64Binary data to 3072 base64 characters.
I added an alert element to the upload control that says 'Maximum image size 2048 bytes'
When I select a file that is withing the xsd limits everything is ok.
When I select a file that is too big I get the "Failed to save" dialog indicating the the data did not pass the xsd check however the alert message does not appear.