from integer to floating point

[Sarah Reichelt]

> The variable names are NOT used anywhere else in the stack. If I past and
> test these handlers in another stack, they work as expected, so it is
> probably due to something in this stack, but what ? I just started with it
> this evening and it contains practically nothing except one slider (calling
> changeclimat with its thumbposition) and six images.

It's an oddity of scrollbars that they appear to produce integers, but
actually they are floating point numbers. Round the thumbPositon
before sending it on and everything should be OK.

Cheers,
Sarah