// JavaScript Document
// Displays the navigation menu for the current html page
function displayMenu () {
	// menu_id is set on each html page, of the format "X_Y" or "X_Y_Z" where X is level 1, Y is level 2, and Z is level 3
	// check the level 1 to see which section to display
	var str = menu_id;
	var level1 = str.substring(0,1);
	var level2 = str.substring(2,3);
	
	// Set the main menu item to selected
	displaySelected(level1+"_0");
	
	// Display this submenu
	var submenu_id = "sub"+level1;
	if (document.getElementById(submenu_id) != null) {
	  var obj = document.getElementById(submenu_id);
	  obj.style.display = "block";
	}
	// If this is a third level menu, also set its immediate predecessor menu item to selected
	displaySelected(level1+"_"+level2);
	// Set this menu item to selected
	displaySelected(menu_id);

}

function displaySelected (id)  {
	var obj = document.getElementById(id);
	var img = obj.getElementsByTagName("img");
	img[0].src = "../images/menu_"+id+"_sel.gif";
}

function menuOver (id)  {
	var obj = document.getElementById(id);
	var img = obj.getElementsByTagName("img");
	img[0].src = "../images/menu_"+id+"_sel.gif";
}

function menuOut (id)  {
	var obj = document.getElementById(id);
	var img = obj.getElementsByTagName("img");
	var level1 = menu_id.substring(0,1);
	var parent = level1+"_0";
	var parent2 = menu_id.substring(0,3);
	
	if (id != menu_id && id != parent && id!=parent2)
	  img[0].src = "../images/menu_"+id+".gif";
}