Inneedoflearning

Hello folks, below is my code and I would like the animation to loop continuously once click

<div class="w3-container w3-center">
    <p id="Demo">Animation is Fun!</p>
    <button class="w3-bar-item w3-green " type="button" onclick="myFunction()" class="w3-button">Touch me</button>
</div>
                        <p>The w3-animate-top class slides in an element from the top.</p>

<script>
function myFunction() {
    var x = document.getElementById("Demo");
    if (x.className.indexOf("w3-animate-top") == -1) {
        x.className += " w3-animate-top";
    } else {
        x.className = x.className.animate(" w3-animate-top", "");
    }
}
</script>

Hello Folks, I am working on package tracking code below but I was overwhelmed and would like you to help me get it fixed.Thanks so much in advance

       
   <form role="form" action="// method="get" onsubmit="return false">
       <div class="input">
           <input type="text" class="input " id="button" placeholder="Tracking Number" name="button_tracking_number" value="" autocomplete="off" maxlength="100" style="border-color: #ff4a00">
           <span class="input">
               <button class="button" id="query" type="button" onclick="return doTrack()" style="background-color: #ff4a00">Track</button>
           </span>
       </div>
       <input type="hidden" name="lang" value="en" />
       <input id="button" type="hidden" name="lang" value="" />
   </form>