5个QQ群里没人解决的Ajax小问题:<ajax基础教程>上的一段代码,请指教~~!

一个静态parseXML.xml文件:

<?xml version="1.0" encoding="UTF-8"?>

<states>

<north>

<state>jilin</state>

<state>heilongjiang</state>

<state>haerbin</state>

</north>

<south>

<state>gz</state>

<state>sz</state>

<state>nn</state>

</south>

<east>

<state>nj</state>

<state>sh</state>

<state>nb</state>

</east>

<west>

<state>qh</state>

<state>wh</state>

<state>kkxl</state>

</west>

</states>

HTML文件里两个Button:

<input name="northButton" type="button" value="显示北部城市" onclick="startRequest("north")" />

<input name="allButton" type="button" value="显示全部城市" onclick="startRequest("all")" />