Super Mario Bros. 3 Tips

Warp Zone Whistles
There are three whistles that I know of
1.In world 1 on level three if you hold down on the white block you will go behind the scenery, but be careful YOU CAN STILL GET HIT, make to the end of the level while still behind the scenery.
2.In the fortress level in world 1 before going through the first door, be sure you have a tail, run towards the lava untill the game starts making a ringing noise then rapidly tap a untill you can go to the right go as far as you can and press up.
3.In world 2 on the map screen go to the far right and use the hammer on the block.defeat the hammer brother there to get the third whistle.
also if you use a whistle to go to the warp zone then use another while in the warp zone you get to go to world 8.