Hi,
it is possible to do that? To open write in/ read to a file?
And the close it?
I'm assuming that is not possible. but who knows?
Thanks in advance.

No. Scratch is a sandbox and so won't allow potentially dangerous operations like that. It could be done with a mod or extension though.

Thanx!
Now, a second, and apparently stupid question:
How should one delete an already created block (procedure - you know)
I'm just searching and right- clicking but I can't delete an already created block.
Thanx in advance.

Just drag and drop the blocks back into the block area to delete them. For procedures you need to delete all the calling blocks before you can delete the procedure itself.

Great!
Thanx!!