basic class problem in Flash Professional

Hi i´m from Germany and i have an problem.

i must edit my files in Flash Professional CS5.5.

so i must my files in Symbols convert and the ckeck boxes from Action Script and picture i have activate.

so in the Basic class field it is this      flash.display.MovieClip

so i need in Basic class field this one     clip

when i write clip in field i become an error message about Basic class has not an definition on class path.

can everywhere me help.

thanks