Do you mean that you are trying to start bean plants indoors? From your description, I expect that they aren't getting enough light, which will cause the "hypocotyl"--the stem below the first pair of leaves--to stretch out and fall over. If possible, I would start over, with the starting pots in a window that gets at least 4 hours of direct sun each day, or under very bright artificial light.

Do you mean sprouting beans in jars. I use a large jar put muslin over the top an secure with a rubber band, this way they can easily be watered(washed) every day and the water tipped out, I find they are usually ready in about five days.

Try eating them a bit sooner before they go stringy. They only need to be about an inch long.