How do I get rid of hole in Thumb Gusset?

How-to Questions
1

I am making my first pair of mittens. I am using the 2 needle method. When I got to the part were you joing the front and back it left a hole in the thumb gusset. How do I fix it so the holes is no longer there?

2

You can pick up an extra st there when you knit the thumb sts, or use the tail from the thumb yarn to close it up.

3

Thanks for your help.