function purposeMenu() {
	if(document.getElementById("sub_otona")) {
		document.getElementById("sub_majime").onmouseover = function() {
			var purposeSub = document.getElementById("purposeNavi");
			purposeSub.className = purposeSub.className.replace(/display_o/g, "display_m");
		}
		document.getElementById("sub_otona").onmouseover = function() {
			var purposeSub = document.getElementById("purposeNavi");
			purposeSub.className = purposeSub.className.replace(/display_m/g, "display_o");
		}
	}
}

try{
	window.addEventListener("load",purposeMenu,false);
}catch(e){
	window.attachEvent("onload",purposeMenu);
}