Hi, David.
When you push the button do you hear the 'click"?
If you do - check the latch handle, it may be bent out of shape.
If there is no clicking sound you need to check if the latch solenoid is getting 120VAC when the button is pushed.
Replace the solenoid if it's burnt
Part number: WB24X5097 
Here are the breakdown diagrams and
Replacement parts for GE JRP03G0J3 - AppliancePartsPros.com
Post the results.
Simon.