Javascript API to add a link to selected text in editor

Hi,

I'm trying to convert selected text in CKEditor into a link using Javascript, but without using the normal insert link dialog that CKEditor provides.  Here's the code I'm trying:

// convert selected text to a link to google
// (doesn't work as hoped: opens the UI to enter the URL)
CKEDITOR.instances.editor1.execCommand('link',
  'http://www.google.com');

// also tried this, but it does nothing
var style = new CKEDITOR.style({ 
  element: 'a', 
  attributes: { 
    href: 'http://www.google.com' 
}});
CKEDITOR.instances.editor1.applyStyle(style);

What is the correct way to programmatically apply a link to the selected text (with no user interaction)?

Many thanks