The page cannot be found when using ReplaceTextarea()

Hi all, I'm using this code to create a fckeditor in javascript -

   
document.getElementById("results").innerHTML="<textarea id='FCKArea' name='FCKArea'>FCK Editor goes here.</textarea>";
var oFCKeditor = new FCKeditor( 'FCKArea' ) ;
oFCKeditor.ReplaceTextarea() ;

But in its place I get 'The page cannot be found'.

It's not because I'm setting the text area using innerHTML as I've tested it doing it the normal html way and I still get the same result.

I'd be very grateful for any help.