table插入tr

在倒数第二行出入

function addIpSegment(id){
    var num=eval($("#segmentNum").val())+1;
    $("#segmentNum").val(num);
    var tr = "<tr class='addIpSegment' id='addIpSegment"+num+"'><td>"+
        "<td>"+
        "<input  id='demandIpStart"+num+"' class='ipSegment' type='text' maxlength='15'>--"+
        "<input  id='demandIpEnd"+num+"' class='ipSegment' type='text' maxlength='15'>"+
        "<a href='javascript:;' class='removeBtn'onclick='removeSegment("+num+")'></a>"+
        "</td>"+
        "<td></td>"+
        "<td>"+
        "</td>"+
        "</tr>";
    var index=$("#demandTable").find("tr").length-3;
    $("#demandTable tr:eq("+index+")").after(tr);
}