Factorial Calculation in Batch

@echo off
setlocal enabledelayedexpansion
::Created By Guerrerohgp
:ini
set result=1
set/p "num=Ingrese su numero: "
if not defined num goto:ini
call:Function_factorial !num!
echo.El factorial de !num! es !result!
pause>nul
exit

:Function_factorial
if %1==1 goto:eof
set/a "result*=%1"
set/a "n=%1-1"
call:Function_factorial !n!