var agt           = navigator.userAgent.toLowerCase();
var is_major  = parseInt(navigator.appVersion);
var is_minor  = parseFloat(navigator.appVersion);
var is_ie         = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1));
var is_ie4up  = (is_ie && (is_major >= 4));

function fix_ie() {
	if(is_ie4up) {
		var elements = document.getElementById('main_menu_ul').childNodes;
		for(var i=0; i<elements.length; i++) {
			elem = elements[i];
			if(elem.nodeName == 'LI') {
				elem.onmouseover = function() {
					submenu = this.getElementsByTagName('ul')[0];
					if(submenu) {
						submenu.style.display = 'block';
					}
				}
				elem.onmouseout = function() {
					submenu = this.getElementsByTagName('ul')[0];
					if(submenu) {
						submenu.style.display = 'none';
					}
				}
			}
		}
	}
}
window.onload = fix_ie;