使用mootool ajax功能显示加载图像

I am using simple ajax functionality using with mootool for display loading image. I have added loading image on onRequest but not working. Is there any wrong in my code. I am getting Uncaught SyntaxError: Unexpected token } after }).send();

My Code:

$('nextButtonForm2').addEvent('click', function(e) {
    e.stop();
    var url = 'index.php?option=com_property&view=property&task=advertisementBox&format=raw';
    var x = new Request({
        url: url,
        method: 'post',
        onSuccess: function(responseText) {
            document.getElementById('advertisement_image').innerHTML = responseText;
        },
        onRequest: function() {
            $('advertisement_image').set('html', '<div><img src='http: 
            //www.example.com/template/xxx/xx/images/loding.gif'></div>');
            }
    }).send();
});

Any ideas or suggestions? Thanks.

Try this:

onRequest: function() {
    $('advertisement_image').set('html', '<div><img src=\"http://www.example.com/template/xxx/xx/images/loding.gif\"></div>');
}

The single quotes in the onRequest function are not properly escaped. Try to escape the inner quotes.