Userlibs + Executables

This may be a stupid question, but at first glance I can't find any answers.

I wrote a program for somebody which used this DLL: http://www.blitzbasic.com/toolbox/toolbox.php?tool=25

When I compiled the code and gave it to him, he said that he got an error 'userlib not found'. How do I correct this?

Global cmd$=Trim(Replace(CommandLine(),Chr(34),""))

Global par1$=ToChar(cmd,0)
Global par2$=ToChar(cmd,1)

If Lower(par1)="file" ;play a sound file
	If FileType(par2)=1
		PlayMusic par2
	EndIf
Else
	SystemBeep(par1,par2)
EndIf

End


Function ToChar$(txt$,which=0,char$=",")
	Local ow=which
	.beginf
	Local ret$="",sloc=0
	Repeat
		sloc=sloc+1
		If Mid(txt,sloc,1)=char Then 
			If which=0 
				If ret=""
					which=ow+1
					Goto beginf
				Else
					Exit
				EndIf
			Else
				which=which-1
				ret=""
			EndIf
		Else
			ret=ret+Mid(txt,sloc,1)
		EndIf
		If sloc>Len(txt) Return Trim(ret) ;If there's no space, return to the end.
	Forever
	Return (ret)
End Function