Without getting too complicated I can come fairly close to the shape I'm looking for.  But, now that I have added extra points, how could I scale this spline alonf the y axis.  Before I added the extra vertexes I could just click and drag on the last vertex, to the right of the Blue or Purple guides; but now hat the others are there, dragging only effects the area bewteen the last vertex and the one before it, rather than from the first to the last vertex?  I tried selecting all of the vertexs, along a line, but that did'nt work.  I also tried to manipulate selected vertexs with the Scale tool, to no end.