Mike

You could add code behind the control for [tracking database] that evaluates
its contents and sets the visible property of the [document hyperlink]
control.

From a usability standpoint, you might want to consider making the [document
hyperlink] control Enabled/Disabled instead of having it wink in and out of
visibility.

Your code could look something like:

   Me.[document hyperlink].Enabled = (Me.[tracking database] <> "no")

(you did say it was a text control, right?  If it were a Yes/No-type
control/field, you'd need to change that code)