To send a text message

On the Messaging screen, tap the New message icon .
Enter a mobile phone number (or a name saved in your Contacts) in the To field.

As you enter the numbers or characters, matching Contacts entry name(s) and number(s) appear. The match can be anywhere in the entry. You can tap a suggested recipient to insert it in the To field, or continue entering the phone number.

NOTE
If you previously started a message to a recipient, then tapped (or pressed) the Back Key , that draft message is automatically displayed for you to continue the message when you start a new message to that recipient. The Draft icon on the right side of the message thread indicates a pending draft message to the recipient.
Tap the text field to start entering your message.

A character counter is displayed to the right of the message field to let you know how many more characters you can type and also the number of pages in the message.
1. To field
  
  Tap here to enter the recipient(s) manually.
2. Message field
  
  Tap here to enter your message.
3. Attachment icon
  
  Tap here to add an attachment to your message.
4. Character counter
  
  Displays the number of characters entered and the amount remaining.
5. Contacts icon
  
  Tap here to enter the recipient(s) by selecting from entries in your Contacts.
If you tap (or press) the Back Key while composing a message, it’s saved as a draft. Tap the message to resume composing it.
Tap the Send button to send the message.

Your message is displayed and responses appear in the same window, creating a message thread with that contact.