local wnd is gui(0).
local btn is wnd:addButton("TEST").
local function click {
	parameter text.
	print text.
}
set btn:onClick to click@:bind("TEST").
wnd:show().
wait until btn:takePress.
wnd:dispose().

local wnd is gui(200).
local function init {
	parameter item.
	parameter width is 0.
	parameter stretch to true.
	parameter align is "center".
	set item:style:align to align.
	set item:style:width to width.
	if width = 0 set item:style:hstretch to stretch.
	return item.
}
local function button {
	parameter wnd.
	parameter text.
	parameter width is 0.
	parameter stretch to true.
	parameter align is "center".
	return init(wnd:addButton(text), width, stretch, align).
}
local function radio {
	parameter lst.
	parameter btn.
	lst:add(btn).
	set btn:toggle to true.
	return btn.
}
local dir is list().
local row is wnd:addHLayout().
local dirPro is radio(dir,button(row,"Prograde",100)).
local dirRet is radio(dir,button(row,"Retrograde",100)).
local row is wnd:addHLayout().
local dirUnl is radio(dir,button(row,"UNLOCK",100)).
local done is button(row,"CLOSE",100).

local function uncheck {
	parameter lst.
	parameter except.
	for btn in lst if btn <> except set btn:pressed to false.
}
local function check {
	parameter lst.
	parameter btn.
	uncheck(list, btn).
	set btn:pressed to true.
}
local function onToggle {
	parameter lst.
	parameter def.
	parameter btn.
	parameter fn.
	parameter on.
	if on { uncheck(lst,btn). fn(). }
	else {
		for b in lst if b:pressed return.
		set def:pressed to true.
	}
}
local function bindToggle {
	parameter btn.
	parameter fn1.
	parameter fn2.
	set btn:onToggle to { parameter on. fn1(btn,fn2,on). }.
	return btn.
}
local function bindToggle2 {
	parameter btn.
	parameter fn1.
	parameter fn2.
	set btn:onToggle to fn1:bind(btn,fn2).
	return btn.
}
local dirToggle is onToggle@:bind(dir,dirUnl).
bindToggle(dirPro, dirToggle, { sas off. lock steering to srfPrograde. }).
bindToggle2(dirRet, dirToggle, { sas off. lock steering to srfRetrograde. }).
bindToggle(dirUnl, dirToggle, { unlock steering. sas on. }).
set dirUnl:pressed to true.

wnd:show().
wait until done:takePress.
wnd:dispose().
unlock all.