function fn_logoff() {
     if (confirm('Logoff krasitys.com?')) {
     	location.href=('/logout.php');
     }
}
function fn_quantity(obj,denominator) {
	if (!denominator) denominator=1;
	quantity=parseInt(obj.value);
    msg="";
	switch (true) {
	  case (obj.value == ''):
	  	break;
	  case (isNaN(obj.value)):
	  	msg=obj.value + " is an incorrect entry";
	  	break;
	  case ((quantity % denominator) !=0):
    	msg="Quantity must be divisible by " + denominator;
	  	break;
	}
    if (msg != "") {
    	alert(msg);
		obj.value='';
    }
}