If I have created a variable in Flash Movie A, how do I get Flash Movie B to recognize the value of the variable?

After that, I would like to have one of three things happen in Movie B, dependant on the value of the variable (1, 2 or 3).

Could someone please give the complete syntax for creating a nested if-then statement?

i.e. if back = 1 then goto and play ...
else
if back = 2 then..., etc.

I can't seem to do it correctly.

Thanks!