I'm creating a graphic for my web page using PhotoPaint 8.

I have a graphic where the top half is white and the
bottom half is ligt blue. The white area is wavey at the bottom where it meets the mauve.

How do I get rid of the jagged edges between the two colors?

I've tried smoothing the edges and it still looks bad and also added a drop shadow (not good now I have jagged edges with a drop shadow).

Any help would be appreciated.