New Transaction

I just upgraded from 2007 to 2010r3 and some aspects of the user 
interface are very strange.  For example, how do I "complete" and enter 
a new transaction without opening yet another new transaction window?  I 
can't find any sort of OK button to complete the transaction I am 
entering.  The only way seems to be to press the Enter key, which closes 
the transaction I'm working on and opens yet another new transaction 
entry.  There must be a better way.

Vic Roberts