How to allow only single autoit compiled exe to run?

[fusion400]

How to allow only single autoit compiled exe to run?

I have an exe that is called autoitrestart.exe and i only want it be able to run in one instance so that

whenever someone by accident clicks the exe it will just exit.

I tried the #SingleInstance Force command but it does not work are there any other options available

that are simple to implement. I just want something that exits the other instance immidiately without

any prompts popping up.

Thanks in advance.

[omikron48]

#include <Misc.au3>
_Singleton("Unique String Here")

[fusion400]

#include <Misc.au3>
_Singleton("Unique String Here")

Thanks alot works great.