What are you trying to achieve?
Sky=createsphere(50) will create a sphere with 50 segments.
I don't know what you are trying to achieve with loadanimimage - which is a 2d command.
Furthermore flip takes a single parameter which is either true or false where false indicates you want the screen to update as fast as possible.
flip blah,sky makes no sense.
LoadAnimImage is used to load an 'image strip' usually where the parameters for the command are:
LoadAnimImage (filename,width,height,first,count)
filename = file you wish to load eg somepicture.bmp
width = width of each frame of animation
height=height of each frame of animation
first can be from 0 to count-1 where count is the number of frames to load
see here:
http://www.blitzbasic.com/b3ddocs/command.php?name=LoadAnimImage&ref=2d_catPerhaps you should ask for information on what effect you are hoping to achieve?