Very frustrating problem with key down event!

I made a keydown event for one of my actors, I went to script editor, and I typed in:
walkright = walkright + 1;
Then I tried it, and it didnt work! WHAT IS WRONG WITH THE CODE?!?!? Thats all,
I will give a point to anyone who can solve this problem. 
walkright = walkright + 1;
Then I tried it, and it didnt work! WHAT IS WRONG WITH THE CODE?!?!? Thats all,

