xml应用程序gui显示后怎么连接 XML 应用程序

x=xmlDoc.getElementsByTagName("CD");
i=0;

function displayCD()
{
artist=(x[i].getElementsByTagName("ARTIST")[0].childNodes[0].nodeValue);
title=(x[i].getElementsByTagName("TITLE")[0].childNodes[0].nodeValue);
year=(x[i].getElementsByTagName("YEAR")[0].childNodes[0].nodeValue);
txt="Artist: " + artist + "<br />Title: " + title + "<br />Year: "+ year;
document.getElementById("showCD").innerHTML=txt;
}

function next()
{ // display the next CD, unless you are on the last CD
if (i<x.length-1)
{
i++;
displayCD();
}
}

function previous()
{ // displays the previous CD, unless you are on the first CD
if (i>0)
{
i--;
displayCD();
}
}