Scrolling only content div, others should be fixed

overflow: auto; adds the scroll when need

#header{
    width: 100%;
    height: 139px;
    background-image: url('images/Header_grey.gif');   
    overflow: hidden;  /* code added to prevent scroll */
}
    
    
#left_side{
    width: 210px;
    height: 700px;
    background-image: url('images/Left_side.gif');
    background-repeat:repeat-y;
    overflow:hidden;  /* code added to prevent scroll */
    position:absolute;
    font-size: 16px;
}
#content{
    height: auto;
    padding: 20px;
    margin-left: 230px;
    margin-right: 20px;
    padding-bottom: 30px;
    overflow: auto;  /* code added */
}