Comme un timer. Mais un chronomètre

label restart,start,quitter
label plus,moins
dim a
a=10

sound 6
file_load 6,"C:\WINDOWS\Media\ringin.wav"

width 0,210
height 0,171
caption 0,"Chronomètre"

edit 1
left 1,5
top 1,5
width 1,192
text 1,""+str$(a)

button 2
left 2,11
top 2,31
width 2,88
caption 2,"+"
font_bold 2
font_size 2,15
height 2,21
on_click 2,plus

button 3
left 3,104
top 3,31
width 3,88
caption 3,"-"
font_bold 3
font_size 3,17
height 3,21
on_click 3,moins

button 4
left 4,15
top 4,83
width 4,173
caption 4,"Restart"
height 4,21
font_bold 4
on_click 4,restart

button 5
left 5,15
top 5,57
width 5,173
caption 5,"Start"
height 5,21
font_bold 5
on_click 5,start

button 7
left 7,15
top 7,109
width 7,173
caption 7,"&Quitter"
on_click 7,quitter

end

restart:
text 1,"10"
return

start:
a=text$(1)
while a>0
text 1,""+str$(a)
wait 1000
a=a-1
end_while
text 1,"0"
play 6
wait 2000
play 6
return

plus:
a=a+1
text 1,""+str$(a)
return

moins:
a=a-1
text 1,""+str$(a)
return

quitter:
terminate