New call

Tapping New call during a call will place the caller on hold, then present the keypad:

Enter the number you're dialling, then tap the call button to the bottom right to initiate a call. If you don't wish to place the call tap the Back button above the dialler, then you'll be presented with the original call screen with the caller on hold.

Otherwise, you can tap the Contacts tab to see an additional screen with two tabs, for Extensions or Contacts.

Extensions

This tab will be displayed initially when you tap the Contacts in the new call screen:

You'll a list of all extensions in your account. Tap an extension to call it, then you'll be able to terminate the new call, or switch to any other held calls at any time.

Contacts

Tapping the Contacts tab at the top of the screen will show a list of configured contacts in your address book in your Dial 9 account:

Just tap a contact to call it, then you'll be able to terminate the new call, or switch to any other held calls at any time.