Hi Art

Once again thanks for the explanation and reply :-)

Mmm the eXclusive OR so the truth table then looks like this ...

A B Result
1 1 0
1 0 1
0 1 1
0 0 0

So ....
The XOR operator returns a 1 when the value of either the first bit or the second bit is a 1.

The XOR operator returns a 0 when neither or both of the bits is 1.

And for a variable swap we could do something like this then ?
X var byte
y var byte

x = x xor y
y = x xor y
x = x xor y

which would be something to consider but NOT to do :-) (just wondering how PBP would react to that one ?)
See here:
http://betterexplained.com/articles/...les-using-xor/
and here:
http://www.topbits.com/xor-encryption.html

Thanks so much once again!

Will definitely give it a bash and post some feedback of the results :-)

Kind regards

Dennis