.tablesorter .tablesorter-header {
    cursor: pointer;
}

.tablesorter .tablesorter-header .sort-icon {
    width: 21px;
    height: 9px;
    display: inline-block;
    background: url(bg.gif) no-repeat center right;
    cursor: pointer;
}

.tablesorter .tablesorter-headerDesc .sort-icon {
    background-image: url(asc.gif);
}

.tablesorter .tablesorter-headerAsc .sort-icon {
    background-image: url(desc.gif);
}