2 problems

[SmileySuzie]

Hi all, so I'm having a couple of problems
1. Phone keeps restarting as I'm using the screen
2. Whilst on a call if I go to use the screen it goes black as soon as I touch it so I'm unable to look at messages, pictures or anything whilst on a call.
Hope someone can help

[_alexdon_]

1.Remove the SIM,check if the same occurs.

2.Do you have a screen protector? I suspect the proximity sensor acting up.