Oh, I know what the problem is, and absol attacker found it too. First of all, move your sprite to the top left corner of the white space. You can do this by using the selector tool, which is the the rectangle with dotted lines. Click on it, and then click right above the top part of the sprite and on the farthest left part of it. In simpler terms, just click on a top left corner that is very close to the sprite. Then move your mose down and to the right, while still holding the left button down. You should see a rectangle forming around your sprite. Keep making it bigger until your entire sprite is in it, and no extra space. Then let go. Then, click on the rectangle and move it to the top left corner of the page. Don't worry, the sprite will move with it. Finally, do what Absol attacker said and click the tiny blue squares at the borders of the white space to move the border up and down or left and right. Do this until you only have the little rectangle with the sprite in it left. Then, click "Save As" and you'll see it says "Save as JPEG" or whatever it is. Well, in that little bar click the little arrow and a menu will come up, which has different save styles. Click "PNG" at the bottom. Then click "Save" and you're done.