Column wise search in HTML Table using TextBox in jQuery

hi , 

I am doing search in my html table in column wise.

in this table i am not able to apply search

Can you please help me how to exclude second row in table.

I exclude first row using this:-

var $rows = $('#table tr').not(':first'); 

But not able to exclude second row.

please help me

<p>Filter table:</p>
<br />
<table id="table" cellspacing="0">
    <tr>
        <th>Code</th>
        <th>First</th>
        <th>Second</th>
        <th>Letter</th>
    </tr>
    <tr>
        <th><input type="text" id="search1" placeholder="Code" /></th>
        <th><input type="text" id="search2" placeholder="First" /></th>
        <th><input type="text" id="search3" placeholder="Second" /></th>
        <th><input type="text" id="search4" placeholder="Letter" /></th>
    </tr>
    <tr>
        <td>AA</td>
        <td>DDD</td>
        <td>NULL</td>
        <td>Z</td>
    </tr>
    <tr>
        <td>EE</td>
        <td>VYX</td>
        <td>ALL</td>
        <td>J,D</td>
    </tr>
    <tr>
        <td>RR</td>
        <td>ROUND</td>
        <td>NULL</td>
        <td>C</td>
    </tr>
</table>
<script type="text/javascript">
    var $rows = $('#table tr').not(':first');
    var filters = { col1: '', col2: '', col3: '', col4: '' };
    $('#search1').keyup(function () {
        var val = $.trim($(this).val()).replace(/ +/g, ' ').toLowerCase();
        filters.col1 = val;
        applyFilters();
    });
    $('#search2').keyup(function () {
        var val = $.trim($(this).val()).replace(/ +/g, ' ').toLowerCase();
        filters.col2 = val;
        applyFilters();
    });
    $('#search3').keyup(function () {
        var val = $.trim($(this).val()).replace(/ +/g, ' ').toLowerCase();
        filters.col3 = val;
        applyFilters();
    });
    $('#search4').keyup(function () {
        var val = $.trim($(this).val()).replace(/ +/g, ' ').toLowerCase();
        filters.col4 = val;
        applyFilters();
    });
    function applyFilters() {
        $rows.show();
        $rows.filter(function () {
            var text = $(this).find('td:nth-child(1)').text().replace(/\s+/g, ' ').toLowerCase();
            return !~text.indexOf(filters.col1);
        }).hide();
        $rows.filter(function () {
            var text = $(this).find('td:nth-child(2)').text().replace(/\s+/g, ' ').toLowerCase();
            return !~text.indexOf(filters.col2);
        }).hide();
        $rows.filter(function () {
            var text = $(this).find('td:nth-child(3)').text().replace(/\s+/g, ' ').toLowerCase();
            return !~text.indexOf(filters.col3);
        }).hide();
        $rows.filter(function () {
            var text = $(this).find('td:nth-child(4)').text().replace(/\s+/g, ' ').toLowerCase();
            return !~text.indexOf(filters.col4);
        }).hide();
    };
</script>