Find MAX in Row of Values

How do I find the MAX value in a row of values?

So far my report looks like this:

               0100     0300     0500    0700

pH             7.2       7.3       7.7       7.2

temp          11         9          9          12       

I need my data to look like this:

               0100     0300     0500    0700     MAX

pH             7.2       7.3       7.7       7.2        7.7

temp          11         9          9          12        12

I've tried using MAX(in[0100], [0300], [0500], [0700])), but that doesn't work.

Thanks!

-Eric