>>>Create an Action Group called Increment varBullet. When the action is fired, you Modify Variable by adding 1 to varBullet. You'll call this action several times.<<<
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>>>For each bullet Text Box, add an action:On Show, Modify Variable, varBullet, Add to Variable, 1 (you could also Set it to 2, 3, etc.), Delay 0.5 seconds<<<
Funny thing is that I started off with the idea of running the Increment varBullet Action Group, but I leave it hanging out there. Where I suggest Modifying the variable when a bullet Text Box shows, just run that action group instead. The delay is still recommended, though.
Kevin