Parse up some URL arguments into an associative array. Won't handle same-name checkboxes, i.e. x=1&x=2, but could be extended to do so... jsperf says the while loop is usually fastest. http://jsperf.com/url-get-string-parsing

url_args.js

var re = new RegExp("([^?=&]+)(=([^&]*))?", "g");
    
function with_regex(url){
    var args = {};
    url.replace(re, function($0, $1, $2, $3) {
        args[$1] = $3;
    });
    return args
}
    
function with_reduce(url){
    return url.split("&").reduce(function(res, bit){
        bit = bit.split("=");
        res[bit[0]] = bit[1];
        return res;
    }, {});
}
    
function with_forloop(url){
    var args = {},
        str_split = url.split("&"),
        i, kv;
        
    for(i = str_split.length; i; i--){
        kv = str_split[i-1].split("=");
        args[kv[0]] = kv[1];
    }
    return args;
}

function with_while(url){
    var args = {},
        str_split = url.split("&"),
        i = str_split.length,
        kv;
        
    while(i--){
        kv = str_split[i].split("=");
        args[kv[0]] = kv[1];
    }
    return args;
}