如何使用JavaScript

Question

以下是我的html文件 -

<script>
    if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp = new XMLHttpRequest();
    }
    else {// code for IE6, IE5
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    xmlhttp.open("GET", "ResourceList.xml", false);
    xmlhttp.send();
    xmlDoc = xmlhttp.responseXML;

    document.write("<table border='1'>");

    var x = xmlDoc.getElementsByTagName("ResourceGroup");

    for (i = 0; i < x.length; i++) {
        document.write("<tr>");
        var y = x[i].getElementsByTagName("ResourcesInfo");
        for (j = 0; j < y.length; j++) {
            if (x[i].getAttribute("type") == "HUMANS") {
                document.write("<td>" + y[j].getAttribute('JobPosition') + "</td>");
            } else {
                document.write("<td>" + y[j].getAttribute('MachineName') + "</td>");
            }
        }
        document.write("</tr>");
    }
    document.write("</table>");
</script>

，要读取的xml文件是 -

<?xml version="1.0" ?>
<resourceslist>
    <ResourceGroup type = "HUMANS">
        <ResourcesInfo JobPosition = "Station Manager" OnDuty= "40"  OnLeave_Local = "1" OnLeave_Oversea = "1" MC = "2" />
        <ResourcesInfo JobPosition = "Deputy Station Manager" OnDuty= "82"  OnLeave_Local = "5" OnLeave_Oversea = "5"   MC = "2" />
    </ResourceGroup>
    <ResourceGroup type = "MACHINES">
        <ResourcesInfo MachineName = "Leopard 2SG"      MachineID = "SB1420J"   MachineType = "Battle Tank"     Available = "15" NotAvailable = "2"  />
        <ResourcesInfo MachineName = "M113A2 ULTRA OWS" MachineID = "SS4020J"   MachineType = "Transport Vechicle" Available = "50" NotAvailable = "21" />
    </ResourceGroup>
</resourceslist>

我是xml的新手，我在找出错误的地方时遇到了很多麻烦。感谢您的帮助。