Hi,
Does anyone know to calculate the reverse of a checksum that was generated with the SYS(2007) function? How are checksums calculated?

Example: aa=val(sys(2007,"4848694856494948556965701264956495752505351565052")) / 15
The calculated value of aa is 2840.9333

Now, to authenticate, what do I do to calculate and get the value 15, when all I know is the 2840.9333 and the string of "4848694856494948556965701264956495752505351565052".

Thanks,
Stanley