function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
	
		sub_nav_society_over = newImage("/images_sub_common/sub_nav_society_over.gif");
		sub_nav_mag_over = newImage("/images_sub_common/sub_nav_mag_over.gif");
		sub_nav_news_over = newImage("/images_sub_common/sub_nav_news_over.gif");
		sub_nav_educ_over = newImage("/images_sub_common/sub_nav_educ_over.gif");
		sub_nav_store_over = newImage("/images_sub_common/sub_nav_store_over.gif");
		home_nav_bg = newImage("/images_nav/home_nav_bg.gif");
		home_nav_over_bg = newImage("/images_nav/home_nav_over_bg.gif");
		blackshadow = newImage("/images_nav/blackshadow.png");

		preloadFlag = true;
	}
}

function loadjscssfile(filename, filetype){

 if (filetype=="js"){ //if filename is a external JavaScript file
  var fileref=document.createElement('script')
  fileref.setAttribute("type","text/javascript")
  fileref.setAttribute("src", filename)
 }
 else if (filetype=="css"){ //if filename is an external CSS file
  var fileref=document.createElement("link")
  fileref.setAttribute("rel", "stylesheet")
  fileref.setAttribute("type", "text/css")
  fileref.setAttribute("href", filename)
 }
 if (typeof fileref!="undefined") {
	  document.getElementsByTagName("head")[0].appendChild(fileref)
	}
}

loadjscssfile("/jQuery/jquery.js", "js") //dynamically load and add this .js file