changing text in a cell if data is entered in another sheet

[paul w]

I have a work book that has 3 sheets named page 1, 2 and 3.
in page 1 cell AU1 the formula is
=IF(COUNTA('PAGE 2'!D6:X38)=0,"1 OF 1","1 OF 2")
In page 2 cell AU1 the formula is
=IF(COUNTA(D6:X38)=0,"","2 OF 2")
this changes page1 cell AU1 from 1 of 1 to 1 of 2 and page 2 AU1 to 2 of 2 if data is entered in ranges d6:x38.
the problem is i now have a 3rd sheet(page3) which i need to change as above if data is entered in its range D6:x38.
how do i modify the above any help would be much appreciated