how to insert in macro - sheetname as function

Please help!

How do I use the name of the first sheet as a variable in macro?

I usually include is this line

Sheets("1st Period").Select

What if the name of the first sheet varies but I will use the same macro?
What should the line look?

I thought of getting the name of the sheet in a cell,, but could not make use of it also,, :P

instead of Sheets("1st Period").select use Sheets(1).select, the first asks excel to call up the sheet named "1st Period" the second asks excel to call up the first sheet (change the number to get sheet 2, 3, 4 etc)