Please help me. I'm trying to find a movie I saw when I was very young. It was kind of kid fantasy movie from late 70's or early 80's. The movie could be older since I saw it on TV.

The main character was a young boy (it's child like 9 or 10 years old). His little sister was kindnapped by something from a fantasy land. The freaks looks like some kind of clowns. There're many different freaks. Each freak has each character.

The boy went to the wonderland to save his sister. I'm not sure about this plot and how he went there.

At the wonderland, many adopted kids were exploited by the freaks.
At the end of the movie, the main character awoke from dream by his older brother or sisters when he was sleeping on autumn leaves.

Everything is not sure cause it's too long time ago.

This isn't sure too but I think there's a sequel. One scene I rememeber is that one of freaks came to real world to meet the boy. The scene was a library or something. I remember the freak's costume. It was striped outfit when the freak put his hand on his pocket, the strip from his sleeve and the pocket matched.

Now, can anybody remember this and tell me what it is?

Please help me, this's bugging me all my life!