function highlight_menu_item(element,image)
{
	
    if (element.className == "MainMenu"){
        element.className = "MainMenuHighlight";
		document.getElementById(image).src = 'site_images/nav_bullet_on.gif';}
    else{
        element.className = "MainMenu";
		document.getElementById(image).src = 'site_images/nav_bullet_null.gif';}
}