js如何获取url传值

<h3>未设置设备：
<a href="javascript:addTab('设备列表','PKE_DeviceContent/PKE_DeviceContent.aspx?Due=未设置')" style="color: red; text-decoration: none;">
<asp:Label ID="yyy" runat="server" Text="Label"></asp:Label>
</a>
</h3>

//js获取url参数值
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 De = decodeURI(request("Due"));//De=‘未设置’