she escaped but was found! now keeping her in?

I moved my bp to a new tank last week and it had been going well until this morning when my wife screamed and I looked to find my bp heading under the refridgerator. I was able to grab her tail and stop her. it took so doing but i was able to get her out unharmed I believe. could see no signs of damage. but my question is how can I prevent this from happening again? it's a 50 gal kritter keeper with the slideing screen on top. she had pushed it open enough to get out. right now i have the sides duct taped. I dont think she can get out now but I need a better fix. any sugestions?

bunjee cords, or buckles. i use the buckles, we got them from a fabric store and it was pretty cheap and i put two on there one on each side of the cage.

if you dont know what i mean by buckles i think that there is a pic of them in my gallery on khentimentius set up if not it kind of looks like book bag straps :)