How can I make an additional form field appear whenever the user clicks a link without refreshing the page?

<div id="textboxes">

<input type="text" name="text1" />

</div>

<a href="#" onclick="return newtext()">Add New Textbox</a>

<script type="text/javascript">

var counter = 2;

function newtext() {

var div = document.getElementById('textboxes');

var tb = document.createElement('input');

tb.type = 'text';

tb.name = 'text' + counter;

div.appendChild(tb);

counter++;

return false;

}

</script>

Customization is up to you.

Edit: Please note that the person below me copied my answer.