I have a client who wishes to use a product called timelock to create a trial use package for their software package. The functions: verifyTimeLock16 parameters (char filename, char password, char string) showMainDialog16 parameters (char password, boolean .T.) My code: clear set library to foxtools lnReturn = SPACE(25) lnVerify = Regfn("verifyTimeLock16","CC@C","I","tl16v20.dll") lnCall = CallFn(lnVerify,"test.tsf","2685978",@lnReturn) **-- lnCall = 1 **-- lnReturn = "768391196779034525797414" lnShow = RegFn("showMainDialog16","CI","L","tl16v20.dll") **-- lnShow = 2 lnShowed = CallFn(lnShow,"2685978",0) **-- lnShowed = 0 As you can see the functions are being registered and the first call succeeds. The call to lnShow fails and returns 0. My Question: The 2nd function requires a boolean parameters, but I can't find a way to do that. I have tried using integer and passind (0 and 1) but the function still fails. What I am overlooking or doing wrong?