Samsung Behold II SGH-t939 - Manual (Page 67)

Entering Text 64
The 123 mode enables you to enter numbers into a text message.
ᮣ Touch SYM/123 then press the numeric keys you want to enter.
Using ABC Mode
To use ABC mode:
1. Touch ABC until the keypad displays.
2. Touch the key labeled with the letter you want. Once for the first letter, twice for the second letter, and so on.