Load multiple bitmaps in movieclip

hi folks,

i just wana know how can i load high res image using loader in only the visible area of the container, just like in this gallery, if you zoom in, only the visible are will load high res image,

[URL=“http://www.chanel.com/catalogue/spring-summer2010/en_GB”]http://www.chanel.com/catalogue/spring-summer2010/en_GB

thanks