anchor function does not render anything on the page

[eluser]zcorbitt[/eluser]
This is my first attempt at CI, but I am having difficulties with the url helper.

I have loaded the url helper in my controller, as instructed in the "Blog" video tutorial. However, when I try to use it in a view it does not render anything at all. The following is how I have it in the view:

anchor("invoice/notes/".$row->InvoiceID, "Notes")