th.header, th.headerSortUp, th.headerSortDown{
    background-repeat: no-repeat;
    background-position: right center;
    cursor: pointer;
}

th.header{
    background-image: url(/static/tablesorter_bg.gif);
}

th.headerSortUp{
    background-image: url(/static/tablesorter_asc.gif);
    background-color: #f5f5f5;
}

th.headerSortDown{
    background-image: url(/static/tablesorter_desc.gif);
    background-color: #f5f5f5;
}