Search in specified column - tablesorter

[losporros]

how do the following??
Make your search by selecting the column

<script type="text/javascript">
$(document).ready(function() {

$("#campo_filtrar").change(function ()
{
$("#campo_filtrar option:selected").each(function ()
{
campo_seleccionado=$(this).val();
alert(campo_seleccionado);
});
});

$("#tableOne").tablesorter({ debug: false, sortList: [[0, 0]], widgets: ['zebra'] })
.tablesorterPager({ container: $("#pagerOne"), positionFixed: false })
.tablesorterFilter({ filterContainer: $("#filterBoxOne"),
filterClearContainer: $("#filterClearOne"),
filterColumns: [0], // Search in the selected column
filterCaseSensitive: false
});

});


</script>

<table>
...........................

Search by: <select id='campo_filtrar'/>
<option value='0'>Name</option>
<option value='1'>Major</option>
<option value='2'>Sex</option>
<option value='3'>English</option>
<option value='4'>Japanese</option>
<option value='5'>Calculus</option>
<option value='6'>Geometry</option>
</select>
<input type='text' id="filterBoxOne" size='30'>
<img id="filterClearOne" src="_assets/img/cross.png" title="Click to clear filter." alt="Clear Filter Image" />



http://beckelman.net/demos/jqueryTableSorterConPaging/default.aspx