Hi guy I know that you can solve this

I am making an led flash through a parallel port now the code which I am using, it send "1" and then stop for some seconds and then again it sends "0" and then stops for some seconds. That is all in a loop like this

Code:
Do
PortOut 888, 1
delay
PortOut 888, 0
delay
Loop Until stopl = True
This delay function is this

Code:
For i = 1 To 1000000
Next i
now I have two command buttons, one is for flashing the led and the other one is for stoping it.

Whenever I press the stop button, it will say that

stopl = true

so the loop will stop

But the problem is that whenver the led starts flashing, my whole program is frozen and I cannot click anywhere.

I know that there is something wrong but i cannot figure it out
Please give me a solution!

Thanks