It's not clear exactly what you want, @aadecarlojr.
If you want the maximum value across all the values of the two given columns then the JSL that @txnelson gave above will work.
If, on the other hand, you want something like this:
A
|
B
|
Max of A and B
|
1
|
2
|
2
|
4
|
3
|
4
|
8
|
7
|
8
|
Then the formula:
Maximum(:A, :B)
will give you that.
-Jeff