Retreiving a single number from a list of numbers ?

[Peter Moscatt]

I am trying to extract a value from a variable that contains more than one
value.

For example:
    If  I assigned the result of wxGetClientDisplayRect() to the var 'a'
like:
        a = wxGetClientDisplayRect()

the 'a' would return something like (0, 0, 800. 540)

How then would I assign the 800 from 'a' and give it to a var called 'b' ??

Regards
Pete