Where did my macro go?

I know it was in the worksheet and I saved the worksheet, but when I closed
the worksheet and reopened it, the macro is now gone.

How do I find it or do I have to re-record it?

Also, how do I make it accessible so others can run it as well (it reformats
the layout of the page and columns and column headers after exporting data
from an Access database into the Excel spreadsheet.

I have it assigned to a button on the toolbar...the button is still there
but the macro is gone and I now get an error message stating the macro cannot
be found...???

Help!