Picaxe project board and programming

I've used a 28 pin picaxe board for this project. Here you have its datasheet:
http://www.picaxe.com/docs/axe020.pdf

In the outputs pins I've connected the three LEDs, the servo and the display.
In the analogue inputs I've connected the three digital sensors of distance, and I've connected the push-button at one of the digital inputs.

These connections are simple, but let's see how to program it.

let b3 = 0
setint %10000000,%10000000 ‘ activate interrupt


inici:
let b4 = b3
let b3 =0
if pina.1=0 then
  high b.7
  inc b3
end if
if pina.2=0 then
  high b.4
  inc b3
end if
if pina.3=0 then
  high b.3
  inc b3
end if
if b3=b4 then
goto inici
end if
low b.7
low b.4
low b.3
if b3=0 then
serout B.5,N2400,(254,1)
pause 30
serout B.5,N2400,(254,128) ; move to start of first line
serout B.5,N2400,("3 spaces left") ; output text
end if
if b3=1 then
serout B.5,N2400,(254,1)
pause 30
serout B.5,N2400,(254,128) ; move to start of first line
serout B.5,N2400,("2 spaces left") ; output text
end if
if b3=2 then
serout B.5,N2400,(254,1)
pause 30
serout B.5,N2400,(254,128) ; move to start of first line
serout B.5,N2400,("1 space left") ; output text
end if
if b3=3 then
serout B.5,N2400,(254,1)
pause 30
serout B.5,N2400,(254,128) ; move to start of first line
serout B.5,N2400,("Any space left") ; output text
end if
goto inici


interrupt:

if pinC.7 = 1 then interrupt ; loop here until the
; interrupt cleared

servo 6, 130
pause 5000
servo 6,210
pause 500
setint %10000000,%10000000 ; re-activate interrupt

return ; return from sub

This is all for today, later I'll upload the video showing how the parking works,