$.extend({

    getUrlVars: function () {

        var vars = [], hash;

        var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');

        for (var i = 0; i < hashes.length; i++) {

            hash = hashes[i].split('=');

            vars.push(hash[0]);

            vars[hash[0]] = hash[1];

        }

        return vars;

    },

    getUrlVar: function (name) {

        return $.getUrlVars()[name];

    }

});

//获取参数对象

alert($.getUrlVars());

//获取参数a的值

alert($.getUrlVar('a'));