Disable image button?

Disable image button?

Hi,

I'm trying to disable an image button using jquery as follows:

      $("#<%=MyButton.ClientID%>").attr('disabled', disabled);

where disabled is passed in as either true/false. This works fine in IE, it seems to disable in firefox, but the cursor still shows as a hand i.e. the user thinks they'll be able to select the buttons. It should be a normal pointer like IE. Any ideas as to why this doesn't work the same way as IE and what I can do to fix it in the simplest way possible?