No problem friends!
Please specify your browser in that you get the problem and paste a part of exact code.
Another thing is that your problem is not clear in the question that why you using margin.
There are no error in your code.But still you can use such like that:
In style or .css file add this
.divclass
{
width:997px;
margin:0px;
padding:0px;
}
<div class="divclass"></div>