Well, I have no time for explaining, anyways, nobody understands my explanations. I'll PM you my whole script. I hope you to have the DS resolution already, if you don't... change the lines 10 and 11 on the Sprite Resizer script for this(if you can't find the script just press Ctrl+Shift+F and type "SpriteResizer" and it should show):
@@width=512
@@height=384