Please help.

My cursor changed and I don't know why. I am using Excel 2003 and when I
mouse over any cell, I am used to seeing the white plus cursor. But for some
reason, I only see the white arrow. After clicking around a little, the
cursor changes to the white hand. And I cannot do an autofill either. Usually
I see the black plus cursor when I autofill, but nothing happens or works.
How can I fix or change this so I see the white plus cursor again? Is this an
Excel problem or an Office problem? Thanks for your help