Sorting on a calculated field

[matpj]

I have a field that uses a DateDiff function.
This works fine and shows me how many days since the last time was booked onto various projects.

I would like to be able to sort by this value in descending order, so I can see the project that has been the most 'idle'.

Crystal does not let me choose this field in the sort window.
can anyone tell me how I can do this?

thanks,
Matt

 

[matpj]

I dno't know what I did, but its fixed now.
I may have removed the "whileprintingrecords;"

Matt