I have say 12 sheets for 12 months in a excel workbook

each sheet has say 4 columns "Activity"(in col A), "Start"(in col b),
"Finish"(in col c), "Status"(in col d)
each sheet has a definite number of rows for data entry and cant
exceed
beyond these values(ex:A7 to A39 for "activity" similarly b7 to b39
for
"start"...)


I want to have a summary sheet with the same 4 columns "Activity"(col
A),
"Start"(col b), "Finish"(col c), "Status"(col d)

I have 2 questions

1) whenever a data entry is made in any of the 12 worksheets (between
rows 7
to 39 for A, B, C, D colms), the same values should automatically be
copied
onto the summary sheet.

2) say for example in 1st sheet a project name "xyz CR" is entered
under Activity, and again to
track for next month in 2nd sheet i enter the same project name "xyz
CR" again under Activity.
This duplicate should not be entered in the summary sheet.