Background-Image in element

Can someone help me to find my Problem ?I have a <img /> and will give him a background-image within a <a> tag.

Here is my example:

<img border="0" style="display:block; width:20px; height:20px; background-color:red; padding:9px; background:url(\'./images/system/button/close/close.png)\' no-repeat" />

Background-Color didn't work to.. :-( My Example is a JavaScript String, thats the reason why I'm escaping the URL

Thank's for help :-)