Top down view with Jumping?

hi everyone, i making a top down platform type game, except i cant get my character to jump properly. he can jump but it kinda suck the way ive done it. my intention was to make it like in the gameboy version of zelda where you can run around from top down but also jump from platform to platform.

use wsad to move and space to jump.

if anyone can help it would be much apreciated

fla included in zip, flash 8.