imessage....not so simple

[Phil in ocala]

Using iMessage for the first time....I enter my email and password under "accounts" in preferences.
Then on the page...I enter the phone number i want the message to go to...then drop to bottom of window and enter the message....NO submit button...NO send button seen....I hit return and the phone number disappears....this software is NOT intuitive as apple used to be....I am looking for ideas...if you dont have a problem kindly refrain from answering this...thanks