Someone

alias calc {
  dialog -m calc calc
}
dialog calc {
  title "Calculator"
  size -1 -1 70 53
  option dbu
  text "Equation", 6, 6 2 53 13
  text "Answer", 7, 6 20 53 13
  edit "", 1, 12 10 50 10
  edit "", 4, 12 27 50 10
  button "Calc", 2, 15 40 20 10, flat
  button "Cancel", 3, 38 40 20 10, flat, cancel
}
on *:dialog:calc:sclick:2:{
  /did -a $dname 4 $calc($did(1)) 
}