MGS style codec

hey everybody, this shouldnt be too hard.

im trying to make a metal gear style codec.
ive setup all the hud widgets and everything i need, i just need to be able to trigger off a call and have specific text appear in the widget.

so basically, i have my codec hud, i want to place trigger boxes around the level and when you step into one it goes ring ring, you hit answer then the codec appears and text that ive got stored in that call trigger is printed on the hud. simples