This sounds like such a simple task, but I defy you to figure it out on your own.
In Dynamics forms, there is the concept that a text field can be linked to it's label, or 'prompt'. There is also the concept that the linked label will then respond in tandem to it's 'linkor', Linking can affect a label's Visible, Editable, and Required properties (read Mariano for more: http://dynamicsgpblogster.blogspot.com/2009/02/importance-of-linking-your-fields-to.html).
At any rate, our job at DynDeveloper is to provide RAD guidance: guidance to get you quickly coding. True to form, here is a short tutorial on how to link text boxes and labels in Modifier