JSFiddle - React, Tailwind, and code Playground

HTML

<label>First Name</label></td>
   <td> <input class="required" type="text" name="firstname"   value="Fill" id="firstname" /><span>(required)</span></td>

JavaScript

$("#firstname").on({
    focus: function() {
        if (this.value==='Fill') this.value = '';
    },
    blur: function() {
        if (this.value==='') this.value = 'Fill';
    }
});