how to add a pop up message when a from is clicked in html code example

Example 1: how to open a new html page on button click in javascript

<button id="myButton" class="float-left submit-button" >Home</button>

<script type="text/javascript">
    document.getElementById("myButton").onclick = function () {
        location.href = "www.yoursite.com";
    };
</script>

Example 2: placeholder text disappear when click in react

placeholder="Search..."
              onFocus={(e) => e.target.placeholder = ''}
              onBlur={(e) => e.target.placeholder = 'Search...'}