访问 iframe 的信息

index.html 里 有个iframe，指向xx.html

<SCRIPT LANGUAGE="JavaScript">
	function test(){
		alert("iframe的 src=" + document.all.bottom.src);
		alert("xx.html 里的js变量aa=" + bottom.aa);
		alert("xx.html 里的input的值mytext.value=" 
            + bottom.document.all.mytext.value);
        //调用xx.html里的f_xx方法
		bottom.f_xx()
	}
</SCRIPT>
<iframe id="bottom" src="xx.html" name="bottom"></iframe>
<button onclick="test()">click me</button>

<SCRIPT LANGUAGE="JavaScript">
var aa = "var in xx.html";
function f_xx()
{
	alert("hello!");
}
</SCRIPT>
<input type="text" name="mytext" value="gogo">