javascript获取url参数的代码

<script language = javascript>
function request(paras){
var url = location.href;
var paraString = url.substring(url.indexOf("?")+1,url.length).split("&");
var paraObj = {}
for (i=0; j=paraString[i]; i++){
paraObj[j.substring(0,j.indexOf("=")).toLowerCase()] = j.substring(j.indexOf("=")+1,j.length);
}
var returnValue = paraObj[paras.toLowerCase()];
if(typeof(returnValue)=="undefined"){
return "";
}else{
return returnValue;
}
}
var theurl=request('url');
var theimg=request('img');
document.writeln("<a href='" + theurl + "' target=_blank><img src=" + theimg + " width=750 height=450 border=0></a>");
</script>