Gap in a loftet surface

Hi,

I created a curve in Rhino and referred it into Grasshopper. I divided the curve and made vertically SDL lines from the points. The length of the lines are controlled by a Bezier graph. I want to loft and make a surface but grasshopper wont let me do that. 

If I move the graph and put in a specific lenght, the surface appears but there is a gap in it. 

Does anybody know what the problem is? :)