Are the background gifs in jqtransform.css necessary?

Are the background gifs in jqtransform.css necessary?

I have just downloaded the jqtransform plugin for styling forms. Could someone tell me whether the background gifs in the jqtransform.css file are necessary e.g. 

.jqTransformInputWrapper {
    background: transparent url(img/input/input_text_left.gif) no-repeat left top;
    height: 31px;
    padding: 0px;
    float:left;
}


or whether this was just included for demo purposes?