function explain(key,key2)
{ 



	var _topmenu = 7

	/*top images over  */       
	var _topImg = document.getElementsByName("Image"+_topmenu)[0].src ;
	var _topimsipath       = _topImg.split("/");  // split 함수사용..     
	var _topimgName        = _topimsipath[_topimsipath.length-1];   // 잘라진 값 배열..
	var _topimsiimgName    = _topimgName.split(".");  // split 함수사용..     
	var _topimsiimgName2    = _topimsiimgName[0].split("_");  // split 함수사용..    
	var _topoverImg        = _topimsiimgName2[0]+"_"+ _topimsiimgName2[1]+"_over."+ _topimsiimgName[1]; 

	document.getElementsByName("Image"+_topmenu)[0].src = "/main/newimg/res/"+_topoverImg +"";

	/*top layer down */
	TopSubMenuChange(_topmenu); 





	var menu_count = 9;
	for(i=1; menu_count > i; i++){
		document.getElementById("leftmenu"+i).style.display = "none"
		document.getElementById("leftmenu"+i+"_").style.display = "block"
	}
	document.getElementById("leftmenu"+key).style.display = "block"
	document.getElementById("leftmenu"+key+"_").style.display = "none"
	



	/* 서브 이미비 롤오버 */
	if (key2 !=null && key2 !=0)
	{
		var _imgpath       =  document.getElementsByName("Image1"+key+key2)[0].src ;
		var _imsipath       = _imgpath.split("/");  // split 함수사용..     
		var _imgName      = _imsipath[_imsipath.length-1];   // 잘라진 값 배열..
		var _imsiimgName = _imgName.split(".");  // split 함수사용..     
		var _overImg       = _imsiimgName[0]+"_over.gif";    
		document.getElementsByName("Image1"+key+key2)[0].src = "/introduction/images/res/"+_overImg +"";

	} 
}
<!-- Last Generated Date :: [2010-02-24 16:32:31 874] -->