Twenty Ten Theme wont allow custom image

All im trying to do is add to header.php a simple line of html code to add an image which is my logo to the file and it won’t display it at all. I don’t know what the deal is.

Here is what im trying to include:

<a href="#"><img src="images/linktoimage.png" alt="Logo of site" /></a>

Anyone else run into the same issue? I’ve been having the run around for a few hours wondering why it won’t allow a simple image via XHTML.