JavaScript: Replace Text Found in a Node and its Subnodes of the DOM Tree

The following examples replaces the letter "l" or "L" with "r" or "R" respectively. It gets a DOM element, and traverses it along with its children, and performs the operation.

function engrish(n)
{
 if(n.nodeType == document.TEXT_NODE)
 {
     n.nodeValue = n.nodeValue.replace(/l/g, 'r').replace(/L/g, 'R');
 }
 else if(n.hasChildNodes())
 {
     for(var i=0; i < n.childnodes.length; i++)
         engrish(n.childNodes[i]);
     }
 }
}