Dynamically append BR tag in DIV using JavaScript

<div id ='dvNames'></div>
<input type="button" onclick="WriteText()" value="Write" />
<script>
function WriteText() {
    var div= document.getElementById("dvNames");
    var br = document.createElement('BR');
    var adnaan= document.createElement('SPAN');
    adnaan.innerHTML = 'ADNAAN';
    var nasir= document.createElement('SPAN');
    nasir.innerHTML = 'NASIR';
    div.appendChild(adnaan);
    div.appendChild(br);
  div.appendChild(nasir);
};
</script>