function highlightModelMenu(highlight) {
	var nav_img = document.getElementById("modellinkimg");
	
	if (highlight) {
		nav_img.setAttribute("src", "images/layout/main_nav/model_hover.jpg");
	} else {
		nav_img.setAttribute("src", "images/layout/main_nav/model.jpg");
	}
}


function highlight(id, highlight) {
	var nav_img = document.getElementById(id);
	
	var dropmenu = document.getElementById("model_drop");
	
	dropmenu.onmouseover = function() {
		this.style.display = "block";
		highlightModelMenu(true);
	}
	
	dropmenu.onmouseout = function() {
		this.style.display = "none";
		highlightModelMenu(false);
	}
	
	if (highlight) {
		switch(id) {
			case "homelinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/home_hover.jpg");
				break;
			case "modellinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/model_hover.jpg");
				dropmenu.style.display = "block";
				break;
			case "companylinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/company_hover.jpg");
				break;
			case "contactlinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/contact_hover.jpg");
				break;
			case "distributorslinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/distributors_hover.jpg");
				break;
			case "newslinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/news_hover.jpg");
				break;
		}
	} else {
		switch(id) {
			case "homelinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/home.jpg");
				break;
			case "modellinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/model.jpg");
				dropmenu.style.display = "none";
				break;
			case "companylinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/company.jpg");
				break;
			case "contactlinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/contact.jpg");
				break;
			case "distributorslinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/distributors.jpg");
				break;
			case "newslinkimg" : nav_img.setAttribute("src", "images/layout/main_nav/news.jpg");
				break;
		}
	}
}


function prepareMainNav() {
    if (!document.getElementsByTagName) return false;
    if (!document.getElementById) return false;
	if (!document.getElementById("main_nav")) return false;
	
	var mainnav = document.getElementById("main_nav");
    var links = mainnav.getElementsByTagName("a");
    
    for (var i=0; i<links.length; i++ ) {
		var linkId = links[i].getAttribute("id");
		
		linkId = linkId+"img";
		
        if (!document.getElementById(linkId)) continue;
        
		links[i].linkId = linkId;
		
        links[i].onmouseover = function() {
            highlight(this.linkId, true);
        }
		
		links[i].onmouseout = function() {
            highlight(this.linkId, false);
        }
    }
}

addLoadEvent(prepareMainNav);