var closeTimer = 0;
var dropDownMenuItem = 0;
function dropDownMenuOpen(id) {	
	dropDownMenuCancelCloseTimer();
	if(dropDownMenuItem) dropDownMenuItem.style.visibility = 'hidden';
	dropDownMenuItem = document.getElementById(id);
	dropDownMenuItem.style.visibility = 'visible';
}
function dropDownMenuClose() {
	if(dropDownMenuItem) dropDownMenuItem.style.visibility = 'hidden';
}
function dropDownMenuCloseTimer() {
	closeTimer = window.setTimeout(dropDownMenuClose, 500);
}
function dropDownMenuCancelCloseTimer() {
	if (closeTimer) {
		window.clearTimeout(closeTimer);
		closeTimer = null;
	}
}
document.onclick = dropDownMenuClose;