Integrate suggestion from review to improve consistency with existing code.
2 var url = document.location.href;
3 var imageUrl = url.replace(/[/][^/]*$/, "/blue-circle-16x16.png");
4 var viewSourceImageUrl = "view-source:" + imageUrl;
5 var html = "<iframe src='#url#'></iframe>".replace(/#url#/, viewSourceImageUrl);