function OAS_RICH(position) {
if (position == 'x21') {
document.write ('<A HREF="http://omnikool.discovery.com/RealMedia/ads/click_lx.ads/science.discovery.com/index.html/218463598/x21/default/empty.gif/7969776743556e514d67514143416b79?x" target="_top"><IMG SRC="http://imagec12.247realmedia.com/RealMedia/ads/Creatives/default/empty.gif"  WIDTH=1 HEIGHT=1 ALT="" BORDER=0 BORDER="0"></A>');
}
if (position == 'Frame2') {
document.write ('<A HREF="http://omnikool.discovery.com/RealMedia/ads/click_lx.ads/science.discovery.com/index.html/482976925/Frame2/default/empty.gif/7969776743556e514d67514143416b79?x" target="_top"><IMG SRC="http://imagec12.247realmedia.com/RealMedia/ads/Creatives/default/empty.gif"  WIDTH=1 HEIGHT=1 ALT="" BORDER=0 BORDER="0"></A>');
}
if (position == 'x20') {
document.write ('<A HREF="http://omnikool.discovery.com/RealMedia/ads/click_lx.ads/science.discovery.com/index.html/1324555573/x20/default/empty.gif/7969776743556e514d67514143416b79?x" target="_top"><IMG SRC="http://imagec12.247realmedia.com/RealMedia/ads/Creatives/default/empty.gif"  WIDTH=1 HEIGHT=1 ALT="" BORDER=0 BORDER="0"></A>');
}
if (position == 'x12') {
document.write ('<img src="/common/sgallery/transp.gif" width="1" height="1" border="0" alt="spacer.shim" />');
}
}