It's "Browse" immediatley above where you click to "add reply", you use that to find the file on your computer and as long as it's not bigger than 100k and the right format it will work. I doesn't need to attach manually, just Browse it.
all your tanks are sooo cool! mine just sucks. I don't have anything for my fish to swim through, or to hide behind, I don't have that kind of money...you guys are really lucky....Hey! does anybody have any CHEAP ideas to make my tank interesting?