howdy! i haven't made an Arcanum mod for over a year now, but if my memory is correct you'll need a script with the same name as the dialog (ie 0001billy.dlg and 0001billy.scr). the script needs to start dialog and that script needs to then be attached to the NPC via the properties in the Map editor. i'll be reinstalling Arcanum and get back to modding soon, so if this doesn't completly answer your question i'll post a better answer. either that or you could review the amtut on the dialog section for a better explanation. i recomend the later. merry modding!
To expand on teddyBR's answer just a bit, the script has to call the dialog at the line you want to start it at, e.g., "dialog 1" would call the dialog at line 1. I also recommend AMTUT, but in addition, I would highly recommend getting DJ_Unique's Script Editor and Zammy's Dialog Editor to do your script editing and dialog editing. You can get both of them at http://www.rpgplanet.com/arcanum/tinker ... erer.shtml if you don't already have them, since our modding tools sections is still being worked on here at T-A. :roll: