[fpc-pascal] Microsecond Delay Suggestions?

[James Richters]

>An alternative would be NtDelayExecution from unit jwanative. Its interval
argument is in multiples of 100ns
>and is essentially what Windows' Sleep() uses internally.
>Note: The first argument "Alertable" determines whether the function can be
interrupted by NtAlertThread 
>(and whatever Windows API functions use that internally).

This sounds like it would work, but I can't figure out how to use it.  Do
you have an example?  
I've tried just a quick test like this:

uses
  windows,jwanative;
Var
  DelayInterval : PLarge_Integer;
  Variable1:integer;
begin
DelayInterval:=1;
Variable1:=NtDelayExecution(true,DelayInterval);
end.

It won't let me set DelayInterval with a constant, I get "Incompatible
Types: got "shortint" expected "Plarge_Integer"  
I really don't undertand these variable types that it wants.