Sometimes in game making it's great to make your own level editor. This allows you to save a lot of time when it comes to making the levels later because you can simply post in the array for each level and load it by numbers. Also good for including in the game so other people can make there own levels and share with friends. Heres one I coded that you can use for free to learn from. The code exports an array to fill the grid, each block number is represented by a number. 1 being a basic block and any other numbers can be added for extra pieces. The array uses a | to seperate the lines to be able to load the level from the text. My game Time Sphere used an advanced version of this engine to make.
Have a go at the editor here - WASD to move in test.
http://www.eggysgames.com/other/Grid%20Editor%20Advanced.swf
Download the .fla file here
http://www.eggysgames.com/other/Grid%20Editor%20Advanced.fla
Ciullo-Corporation
Nice... a bit antiquate maybe :)
EggysGames
Well it's more for beginners to intermediate. Though yes it is a little outdated now for a more experienced developer.