Pop Up not working

I have been trying to fix a bunch of problems on this site. this is my sandbox/dev server for my parent website voltaoil.com. So if you click on Order Fuel, a pop up with a form appears. Right now, nothing is appearing. I have the button set up correctly with css and it should be opening the box, but all it does is darken the background and then nothing. Can you tell me what you think is going on? I have disabled all other plugins except a few. Thank you!