update.html

<html>
    <title>Update Search Engine</title>
    <script src="jquery.min.js"></script>
    <link rel="stylesheet" href="">
    <style>
        body{
            display: flex;
            flex-direction: column;
            justify-content: center;
        }
        .f{
            display: flex;
            flex-direction: row;
            justify-content: center;
            margin-top: 30px;
        }
        form input[type=text]{
            width: 500px;
            height: 60px;
            padding: 15px;
            border:none;
            border:1px solid #ddd;
            display: block;
            margin: auto
        }
        :root{
        --site-color:#66bb6a;
        --site-hover-color:#5da960;
        --site-active-color:#43a047;
    }
    .btn {
        border:none;
        width: 260px;
        font-size: 15px;
        outline:none;
        padding: 10px;
        border-radius: 3px;
        cursor: pointer;
        display: inline-block;
        margin:0 auto;
    }
    .btn-default {
        background: var(--site-color);
        color: #fff;
    }
    .mess{
        padding: 40px 0;
        font-size: 20px;
        color: #43a047;
        text-align: center;
    }
    </style>
    <body>
        <form action="" id="myForm">
            <div class="mess"></div>
            <input type="text" name="" id="" placeholder="Enter Search engine URL">
            <div class="f">
            <button type="submit" id="UpdateFile" class="btn btn-default"> Update Now </button>
            </div>
        </form>
    </body>
    <script>
        $("#myForm").on("submit",function(e){
            e.preventDefault();
           $.ajax({
               method:"POST",
               url :"file.php",
               data:"m="+$("form input").val()
           }).then(function(res){
              console.log(res)
              if(res.toLowerCase() === "success"){
                $(".mess").text("Successfully Updated !");
                $("#myForm").trigger("reset");
              }
           })
        })
    </script>
</html>