$(function(){
        var str="<xml><result><NewDataSet><Table><UserName>test1</UserName></Table><Table><UserName>test2</UserName></Table></NewDataSet></result></xml>";
        var str1="<xml><result><NewDataSet><Table1><UserName>test1</UserName></Table1><Table1><UserName>test2</UserName></Table1></NewDataSet></result></xml>";
        $(str).find(‘Table‘).each(function(){
             alert($(this).children(‘UserName‘).text());
        });
        $(str1).find(‘Table1‘).each(function(){
             alert($(this).children(‘UserName‘).text());
        });
    });

$(function () {
        var str = "<xml><result><NewDataSet><Table><UserName>test1</UserName></Table><Table><UserName>test2</UserName></Table></NewDataSet></result></xml>";
        var a = $.parseXML(str);
        $(a).find(‘Table‘).each(function () {
            alert($(this).children(‘UserName‘).text());
        });
});

alert($(str).html());  

//<result><newdataset><username>test1</username><table></table><username>test2</username><table></table></newdataset></result>