Use the following options to make calls:

Enter the number you wish to dial. If you make a mistake while dialing, use the backspace softkey. When you are finished, press the Call button or the Dial softkey. 

To place a call while another call is active, put the active call on hold and press the New Call softkey.

Use the Redial soft key, to dial the last number placed from the phone. 

For quick access when the phone is idle, press the DOWN button for Speed Dials and the UP button for Placed Calls.