大家帮我解释解释这个JAVASCRIPT函数
function downfile()
{
var filepath=escape(document.getElementById("wavpath").value);
var width = '500px';
var height = '370px';
var arr = new Array(filepath);
var handle = showModalDialog('download.html',arr,'help:no;center:yes;dialogWidth:'+width+';dialogHeight:'+height+';status:0');
}