fires before the popup is hidden
myPop.attachEvent("onBeforeHide", function(type, ev, id){
return true; // return false;
});
Parameters:
type - (string) specifies the reason of that popup will be hidden. Can have one of 3 values:
click - the user has clicked on the document body outside the popup;
esc - the user has pressed the 'Esc' key;
select - when a list is attached to the popup - the user has selected any option from the list.
ev - a native event object
id - the id of the clicked item. For the 'select' type only
Description: