If you don't use @xxx in front of the variable name it will work - xxx. If you use @xxx the last values you entered are remembered. Don't mix @xxx and $xxx like this - I recommend you stay with @xxx. However, you must assign the @xxx values before the dialog first runs - like this [###=changes]
choose=[ "Frente 1", "Frente 2" ]
@choose="Frente 1" ### set initial [default] @choose
enums=[choose.join("|")] ### you just could use emuns=["Frente 1|Frente 2"]
prompts=["TIPO","Ancho","Alto","Espesor"]
@a=600.mm if not @a ### set defaults for @a - any changes to @a will be remembered for that session of SUp...
@b=709.mm if not @b ###
@c=19.mm if not @c ###
values=[@choose, @a, @b, @c]###
results=inputbox(prompts,values,enums,"Parametros del frente")
return nil if not results ### 'nil'
@choose,@a,@b,@c=results ### $a >>> @a etc
########### Frente 1
pz=[]
pz[0]=[0,0,0]
pz[1]=[100.mm,0,0]
pz[2]=[100.mm,-@c,0]###
pz[3]=[0,-@c,0]###
edges=entities.add_curve([0,560.mm,0],[@a,560.mm,0],[@a,560.mm,@b],[0,560.mm,@b],[0,560.mm,0])### a >>> @a etc
facez=entities.add_face(pz)
facez.followme(edges)
### etc etc
