How to replace a element using javascript

We use replaceChild() to replace elements

 <div id="div1">
        <p id="p1">TechFunda.</p>
        <p id="p2">DotNetFunda</p>
    </div>
    <script>
        var a = document.createElement("p");
        var b = document.createTextNode("ITFunda");
        a.appendChild(b);
        var c = document.getElementById("div1");
        var d = document.getElementById("p1");
        c.replaceChild(a, d);
    </script>

We created element p with text as ITFunda by using replaceChild(a,d); it replaces the value TechFunda with ITFunda