Prototype wrap() Method

Syntax:

element.wrap(element, wrapper[, attributes]);

OR

someElement.wrap(wrapper[, attributes]);

Return Value:

An HTML element.

Example:

<html>
<head>
<title>Prototype examples</title>

<script type="text/javascript" 
   src="/javascript/prototype.js">
</script>
<script>

function showResult()
{
   $('test').wrap( $("bold") );
}

</script>
</head>

<body>

  <p id="test">Formatted Paragraph</p>

  <b id="bold">Above Paragraph should be wrapped here....<br />
  </b>

  <br />

  <input type="button" value="Click" onclick="showResult();"/>

</body>
</html>

To understand it in better way you can Try it yourself.