In your .GotValue event, you need to use if/then/elseif blocks instead of nested if/then blocks.
A test for tag = 'Password' will never succeed inside the then socket of a test for tag = 'UserEmail'.
P.S. Please read http://www.appinventor.org/bookChapters/chapter18.pdf
from App Inventor 2 Book: Create Your Own Android Apps
from FAQ Section: Books, Tips, Tutorials for AI2