How do you make a cobblestone genorator in minecraft?

For the water, dig 1 block down, and then next to it dig 2 blocks down, like a staircase. Place the water on the top of the "stairs". Then, go next to the block where the end of the "stairs" are. Leave this block like it is. Then go over one more block and dig down 2 blocks. Take lava and right click the top block. Dig out the dirt block in the middle of the generator and cobblestone should appear. Keep mining that block. You now have a working cobblestone generator!