function getKeyCode(e)// v1.0
{
	if (window.event)
	   return window.event.keyCode;
	else if (e)
	   return e.which;
	else
	   return null;
}
function keyRestrict(e, validchars) 
{
	var key='', keychar='';
	key = getKeyCode(e);
	if (key == null) return true;
	keychar = String.fromCharCode(key);
	keychar = keychar.toLowerCase();
	validchars = validchars.toLowerCase();
	if (validchars.indexOf(keychar) != -1)
		return true;
	if ( key==null || key==0 || key==8 || key==9 || key==13 || key==27 )
		return true;
	return false;
}