get arguments

arg.js

function arg(type) {
    var r,t = Object.prototype.toString;
    [].forEach.call(arguments.callee.caller.arguments, function (a) {
        if (!r && t.call(arguments[0]).replace(/^[^\s]+\s([^\]]+)]/ig,"$1").toLowerCase() === type.toLowerCase()) r = a;
    });
    return r;
}