If I'm remembering right those screen tops use a spline to hold in the wire screening just like a normal window screen. you could buy a new screen and some spline at home depot and repair it yourself. very simple you just cut a piece a little bigger then the lid then wedge the new spline in the crack to hold it in place. trim off the leftover screen that hangs out and your done. they have a little tool to put the spline in it looks like a little mini pizza cutting wheel. but you could use a butter knife or something like that to wedge it in. if your not handy most glass shops will put new screens in frames.