Pixmaps on the TImage

Hi, anybody can tellme wich field of the TImage class keeps the pixmaps of the animated images?

In the blitzwiki says this

# masks:TPixmap[] : Array of image masks for each frame

but when i try something like

ConvertPixmap(sp_image.masks[1],PF_A8)

tellsme that the identifier masks is not found :/

Did you try this first?
ConvertPixmap(sp_image.masks[0],PF_A8)

Field pixmaps:TPixmap[]