ajax help: replacing "loading, please wait" with a simple 'loading' animation gif

Using ajax to load my pages without changing the URL. anyway, when they load there is a default 'Loading content - please wait' (middle of code below). I simply want it to display a loading animation. it will look much more professional. any ideas to simply call an image?

function ajax_loadContent(divId,url,callbackOnComplete)
{
	if(enableCache && jsCache[url]){
		document.getElementById(divId).innerHTML = jsCache[url];
		ajax_parseJs(document.getElementById(divId))
		evaluateCss(document.getElementById(divId))
		if(callbackOnComplete) {
			executeCallback(callbackOnComplete);
		}		
		return;
	}
	
	var ajaxIndex = dynamicContent_ajaxObjects.length;
	document.getElementById(divId).innerHTML = 'Loading content - please wait';
	dynamicContent_ajaxObjects[ajaxIndex] = new sack();
	
	if(url.indexOf('?')>=0){
		dynamicContent_ajaxObjects[ajaxIndex].method='GET';
		var string = url.substring(url.indexOf('?'));
		url = url.replace(string,'');
		string = string.replace('?','');
		var items = string.split(/&/g);
		for(var no=0;no<items.length;no++){
			var tokens = items[no].split('=');
			if(tokens.length==2){
				dynamicContent_ajaxObjects[ajaxIndex].setVar(tokens[0],tokens[1]);
			}	
		}	
		url = url.replace(string,'');

Code (markup):

 

document.getElementById(divId).innerHTML = 'Loading content - please wait';
->

document.getElementById(divId).innerHTML = '<img src=/load.gif />';