// This javascript function changes the display property for the submenus from none to block 
// It allows a drop down menu to be displayed when the main emnu is hovered

function showMenu(id_menu){
var my_menu = document.getElementById(id_menu);
if(my_menu.style.display=="none" || my_menu.style.display==""){
	my_menu.style.display="block";
	} else { 
	my_menu.style.display="none";
	}
}