I search this here and there in net. Also found many. But most of them were not working.Soo for making this thing easy now I am here.I made it by getting help from many sites. The code for how to load a css file by java script is given below.Just add the code in your header tag.And also make a style.css file in the same directory of the html file.
<script type="text/javascript">
<script type="text/javascript">
var callbackFunc = function(){
//alert("Yes It worked");
};
//alert("Yes It worked");
};