x Notation Next to Note?

[powertoold]

Hello,

I am looking at the Fantasie Impromptu sheet music, and I see these small "x"s next to some notes. What do they mean?

Thanks,

[desanto]

They are double sharps. If a # raises a note a half-step, a double sharps (x) raises it 2 half-steps.

[powertoold]

Thanks desanto