<script type="text/javascript">  
function hideLoading()  
{  
document.getElementById('pageIsLoading').style.display = 'none';  
}  
</script>

<div id="pageIsLoading" style="position:absolute;  
display:block;  
padding-left:44px;  
padding-right:12px;  
width:auto;  
height:46px;  
line-height:46px;  
border:1px solid #890000;  
color:#000000;  
font-weight:bold;  
background-color:#e5e5e5;  
background-image: url(http://www.путь_к_папке_images/имя_картинки.gif);  
background-position: 6px center;  
background-repeat: no-repeat;">  
<script type="text/javascript">  
if (typeof window_width == 'undefined' || typeof window_height == 'undefined')  
{  
var window_width; var window_height;  
if( typeof( window.innerWidth ) == 'number' )  
{  
window_width = window.innerWidth; window_height = window.innerHeight;  
}  
else  
if(document.documentElement && ( document.documentElement.clientWidth ||  
document.documentElement.clientHeight ) )  
{  
window_width = document.documentElement.clientWidth;  
window_height = document.documentElement.clientHeight;  
}  
else  
if(document.body && ( document.body.clientWidth ||  
document.body.clientHeight ) )  
{  
window_width = document.body.clientWidth;  
window_height = document.body.clientHeight;  
}  
}  
var left = Math.round((window_width - 200) / 2);  
var top = Math.round(((window_height - 46) / 3) + 46);  
document.getElementById('pageIsLoading').style.left = left+'px';  
document.getElementById('pageIsLoading').style.top = top+'px';  
</script>  
Загружается... Ждите...  
</div>

<script type="text/javascript">  
if (window.addEventListener) {  
window.addEventListener('load', hideLoading, false);  
}  
else if (window.attachEvent) {  
var r = window.attachEvent("onload", hideLoading);  
}  
else {  
hideLoading();  
}  
</script>