function GetQueryString(name) {

    var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");

    var r = window.location.search.substr(1).match(reg);  //获取url中"?"符后的字符串并正则匹配

    var context = "";

    if (r != null)

        context = r[2];

    reg = null;

    r = null;

    return context == null || context == "" || context == "undefined" ? "" : context;

}