Dialog function with message table

I'm looking to creating a simple dialog system that when approaching an NPC it displays a icon that indicates to press a button to talk. When doing so, I want the screen to pause until the dialog is finished and the user presses the key again.

Would like to create it as a function so that I can have different NPCs call it with a message ID and assuming a message table to contain the message text.

Can anyone recommend a simple way to do this or recommend a tutorial? I seem to struggle with finding tutorial that meet my needs.

Thanks!

You could store all your NPC messages in an array. Then its just a case of selecting which message to display.