how to prevent multiple keypress

[benshaty]

Hi,
Im using this awsome script for keyboard popups. I set the "H" key for help window. My problem that if you long press "H"key the popup go crazy (show / hide evey second). I tried: $(document).ready(function(){
$(document).on('keypress',function(e){
var keyPress= String.fromCharCode(e.which);
key.unbind(keyPress);
});
});`

But it didn`t work.
what can i do to fix it?
thanks in advance