Retrieve twitter image using API 1.1 in javascript

[TEGUser]

I would like to retrieve the user image from API 1.1 using Javascript. I have consumerKey, consumerSecret, oAuthAccessToken, oAuthAccessTokenSecret available. Previously with 1.0 I was doing the following:

function pullTwitterImage(twitteruser) {		
		$.ajax({
			url : 'http://api.twitter.com/1/users/lookup.json?screen_name='
					+ twitteruser+ '&callback=?',
			type : 'GET',
			dataType : 'json',
			success : function(data) {
				data[0].profile_image_url ;
			}
		});
	}

Please help.