i cant get VexNet to work with 2 controllers do I need 2 keys conected to the one?
Did you pair the cortex with the main joystick?
by vexnet keys yes
Do you actually have code for a partner joystick?
To install and use a partner joystick make sure that firstly your original joystick is paired properly and that you have connected it to that robot through either a orange programming cable or vexnet keys. Now to add a partner joystick connect a Partner cable from your Partner Joystick to your main joystick. Now
Programming your Robot to use the partner joystick (if your using RobotC at least) is as easy as adding Xmtr2 to the end of BtnXX or ChX. e.g.
would use the down button on button set 5 on the second controller.
Steps for pairing your controller and using a partner controller, along with troubleshooting advice is available in this guide: