老师，这段代码未修改，报错了，请老师帮忙看一下，谢谢
Uncaught TypeError: $(…).unslider is not a function
at HTMLDocument. ((index):278)
at j (jquery.min.js:2)
at Object.fireWith [as resolveWith] (jquery.min.js:2)
at Function.ready (jquery.min.js:2)
at HTMLDocument.J (jquery.min.js:2)

        $('.imgslide').unslider({
            speed: 500,               //  The speed to animate each slide (in milliseconds)
            delay: 3000,              //  The delay between slide animations (in milliseconds)
            complete: function () {
            },  //  A function that gets called after every slide animation
            keys: true,               //  Enable keyboard (left, right) arrow shortcuts
            dots: true,               //  Display dot navigation
            fluid: false              //  Support responsive design. May break non-responsive designs
        });