Parse querystring javascript

parse.js

var parseQuery = function(uri) {
    var query = {};

    var uri = uri.split('?');
    if(uri.length == 0) return null;

    var rawQuery = decodeURIComponent(uri[1]);

    rawQuery = rawQuery.split('&');
    if(rawQuery.length == 0) return null;

    for (var i = 0; i < rawQuery.length; i++) {
        var keyValue = rawQuery[i].split('=');
        query[keyValue[0]] = keyValue[1];
    }

    return query;
}