function openNavDropdown(p) {
	var divs = document.getElementById("top").getElementsByTagName("div");
	for(i = 0; i < divs.length; i++) {
		if (divs[i].className == 'nav-dropdown' && divs[i].id != 'nav-dropdown-' + p) {
			divs[i].style.display = 'none';	
		}
	}
	if (document.getElementById("nav-dropdown-" + p)) document.getElementById("nav-dropdown-" + p).style.display = 'block';
}