(mred:get-single-choice message caption choices parent x y centre width height) -> string or null
message : string
caption : string
choices : list of strings
parent = the current active frame : wx:window object or null
x = -1 : small integer
y = -1 : small integer
centre = #t : boolean
width = 150 : small integer
height = 200 : small integer
This is the same as
wx:get-single-choice except that, if the user resizes the dialog box, the elements inside
the dialog box will re-size themselves as well.