That's not legal HTML. First, get into the habit of quoting your attributes, so that would be something like <a href=" ... ">. Then, recognize what characters need to be HTML-entitized. And actually, in that case, since single quote in a double-quote attribute value is safe, you might not need to change anything.

Oh, and this isn't Perl related at all. It's an HTML issue, so check sites like http://htmlhelp.com and such.