IF Nested Function to display text when 3 linked sheets show the same value.

Sorry about the heading,

What I'm trying to do is make sure that a value is only returned when the 3 linked sheets show the same value in this case a date.

For example when the 3 linked sheets show March 2008 then March 2008 is displayed, in any other case nothing is shown or a fasle value such as ,"Please Check Month End".

=IF(AND('[CAA Spreadsheet (3).xls]Return'!$E$5='[CAA Spreadsheet (3).xls]Return'!$E$5,'[CAA Spreadsheet (2).xls]Return'!$E$5='[CAA Spreadsheet (1).xls]Return'!$E$5),'[CAA Spreadsheet (3).xls]Return'!$E$5,"Please Check Month End")

The formula above I'm using works fine except when a value is entered into workbook '[CAA Spreadsheet (3).xls', no matter what values are in sheet (1) & (2), the cell copies value (3).

Please help someone?

=IF(AND('[CAA Spreadsheet (3).xls]Return'!$E$5='[CAA Spreadsheet (3).xls]Return'!$E$5,'[CAA Spreadsheet (2).xls]Return'!$E$5='[CAA Spreadsheet (1).xls]Return'!$E$5),'[CAA Spreadsheet (3).xls]Return'!$E$5,"Please Check Month End")

Is the condition in Bold correct? I suppose a cell is always equal to itself...