just a minor detail,

if I zoom in too much in a graph, I'll recieve an overflow error, and the graph will crash (in fact the page will no longer respond).
This is no real issue - just an information to you.

Don't know how to insert an image of the error message, but it says (translated from Danish), "CriticalError, Overflow error, ControleCanNotBeDisplayed"

Thanks for a great program!