ActionScript 2.0 :: Show Or Load Thumbnails OnRollOver?

I'm using Flash MX 2004 and actionscript 2.0 and have been working with the xml and adding thumbnails to the photo gallery tutorial in Kirupa. What I'd like to do is only show the thumnails onRollOver and then have them go to open a new page outside of the flash site onRelease. So far I found one solution for the onRollOver but I'm not sure it's the best one:

Code:
clip.onRollOver = function() {
this._alpha = 100;
};
clip.onRollOut = function() {
this._alpha = 0;
};

This works great but with one big hitch. It loads all the thumbnails first and then once I run over all of them it hides and shows them onRollOver and onRollOut. Is there a way to hide them when the page first loads and then only start showing them onRollOver? Is there a way to create a mask hiding everything until onRollOver or possibly a setting for the initial mc.borderFill that would create that effect? Or would it be better to try to figure out how to load them onRollOver. The other part is the link to another site onRelease. I have the links setup in my xml but not sure how to set up a geturl onRelease with _blank to read into the actionscript. I'm very new to working with xml and actionscript.