I promise this is way easier than it sounds. I wouldn't steer you wrong. When I had glass cages, I installed a uvb light inside of each of them, since the screen blocks out uvb. I then just had the basking light dome sitting on top of the screen. This is super easy to do. You can do it in like ten minutes, tops.
1. Industrial strength velcro, allso called heavy duty velcro. This is what I used to use and never had one issue with it. Alternatively, you can use a couple of zip ties. Neither way is wrong.
2. A Repti Sun 10.0 T8 light from Amazon (cheaper than in pet stores) or an Arcadia T8 from www.reptilebasics.com. Either works very well, I use both and never had issues with either brand.
3. A Grow Light from Walmart. They're like $10 or a blacklight fixture from Amazon. As longa s the fixture says T8, it will work.
Click this link for the light:
So you've got all your stuff. Now what? I'll make you a list to make it easy.
1. Pop the plastic cover off the light fixture and take the bulb out that it came with. Throw the bulb and the cover in the trash.
2. Take your Repti Sun bulb and put it in the fixture. Slightly turn it back until it sorta "clicks" in place.
If you're using velcro:
Take your velcro strips and put one part on the back of the fixture, across the length of it. Put the other part on the top of the back wall of the cage, inside the cage.
Press the fixture firmly against the velcro, making it "lock" to the glass. Super easy. Press firmly. Take likes a minute. Now make one small hole in the end corner of the screen and run the cord up and through. Presto. You have uvb inside of your dragon's cage.
If you're using zip ties:
Use the small size zip ties and they'll fit through the top of the screen. Position your fixture inside of the cage and run zip ties around the fixture, up through the hole, and pull tightly to "lock" the tie.
Make a small hole in the bottom corner of the screen to run the cord though.
Presto, you can now put your lid back on and you have uvb inside of your cage. Your dragon will thank you.