I'm working with one workbook - two or more worksheets - one cell on each
worksheet. I would like to edit the cell on any one of the worksheets and the
change effect all of the worksheets no matter which worksheet is edited. Plus
be able to repetitivily edit the cell from the same and/or different
worksheet.

I have been playing with:

sheet1
a1=sheet2$a$1

sheet2
a1=sheet1$a$1

but I can only edit one or the other once using Excel 2003.