Oven wont work but the rest does?

I have a Diplomat softline 720G gas oven grill. The problem I have it the gas hobs all work the grill lights and the LCD display is fine. The problem is the oven part. I was trying to light it but was not getting anywhere. the oven light was coming on and it was trying to ignite but now nothing. When I press the knob in its not doing nothing. No Gas No Ignite sound. How can I fix this?