You could turn the following:
if (again1 == "n" || again1 == "N")
if (again.ToUpper() == "N")
and it would take whatever was in the variable 'again' and capitalize it for the comparison. It's important to note that it wouldn't save it as upper case beyond this statement. For that you would need to do
again = again.ToUpper()
I hope that's helpful.