Input textfield (w/dissapearing pre-filled text)?

Can this be done easily?

Basically I want an input textfield that is pre-filled with some text. I want this pre-filled text to dissapear when the input textfield recieves focus (and if possible re-appear if the text field losses focus without having any text entered in to it).

Right now I’m thinking of having the pre-filled text inside a MC that sits on top of the input textfield and dissapears on mouse over, and re-appears on mouse out after checking if there is any text in the textfield. I was just wondering if there was a cleaner way of doing this?