Resend verification code after jq write code and click 60 seconds

A part .html

 <Div class = "f21"> Get codes </ div>

 

Part two .css // Do not forget to introduce yourself to write css

 .f21{

    height: 36px;

    line-height: 35px;

    width: 125px;

    margin-right: 55px;

    margin-top: 20px;

    background-color: #e5e5e5;

    font-size: 15px;

    border: 1px solid #e5e5e5;

    text-align: center;

    color: #c7000b;

 }

Three. Js part // js library and introduced himself wrote js

var timer="";

was nums = 60;

var validCode = true; // this variable is defined for the subsequent processing is repeated click event

$(".f21").on('click',function(){

            console.log("111");

            var code=$(this);

            if(validCode){

                validCode = false;

                timer=setInterval(function(){

                    if(nums>0){

                        nums--;

                        code.text (nums + "after the second re-transmission");

                        code.addClass("gray-bg");

                    }

                    else{

                        clearInterval(timer);

                        nums = 60; // reset back

                        validCode=true;

                        code.removeClass("gray-bg");

                        code.text ( "send a verification code");

            }

                },1000)

            }

            

        })