/**
 * Function for hightlighting and dimming menu items
 */
function menu_hover(elem, type, background_color, font_color) {
    if (type == 'in') {
        elem.style.background = background_color;
        if (font_color != '') {
        	elem.style.color = font_color;
        }
    } else {
        elem.style.background = background_color;
        if (font_color != '') {
        	elem.style.color = font_color;
        }
    }
}