function DropDownMenuShow(id)
{
	var element = document.getElementById(id);
	if (element != undefined)
		element.style.visibility = 'visible';
}
function DropDownMenuHide(id)
{
	var element = document.getElementById(id);
	if (element != undefined)
		element.style.visibility = 'hidden';
}
function DropDownMenuHideAll()
{
	DropDownMenuHide('menu-dropdown-tour');
	DropDownMenuHide('menu-dropdown-support');
	DropDownMenuHide('menu-dropdown-mozenda');
}