function pulldownMenu(){
	gNav = document.getElementById("gNavi");
	for (i=0; i < gNav.getElementsByTagName("ul").length; i++){
		gNav.getElementsByTagName("ul")[i].style.display = "none";
	}
	
	document.getElementById("gn-labo").onmouseover = function () {
		document.getElementById("gn-labo").getElementsByTagName("ul")[0].style.display = "block";
	}
	document.getElementById("gn-labo").onmouseout = function () {
		document.getElementById("gn-labo").getElementsByTagName("ul")[0].style.display = "none";
	}

	document.getElementById("gn-intro").onmouseover = function () {
		document.getElementById("gn-intro").getElementsByTagName("ul")[0].style.display = "block";
	}
	document.getElementById("gn-intro").onmouseout = function () {
		document.getElementById("gn-intro").getElementsByTagName("ul")[0].style.display = "none";
	}

}

if(window.addEventListener) {
	window.addEventListener("load", pulldownMenu, false);
}
else if(window.attachEvent) {
	window.attachEvent("onload", pulldownMenu);
}