//判断父页是否存在某个javascript函数

    function fnExist(fnName) {

        //return fnName in this && eval(fnName) instanceof Function;

        return fnName in this && typeof (eval(fnName)) == "function";

    }  

//重载thickbox方法，实现刷新页面

    function tb_remove() {

        if(fnExist("selectDepartment") == true) {

            selectDepartment();

        }

    }