Help! ...Should be an easy one...

Hey!
I'm currently making a small website to display my portfolio and resume and other junk. I've made a scrolling picture gallery to diplay my work and would like it to open in a seperate window which I have already done like so...

portfolio.onRelease = function() {
getURL("Gallery.swf", "_blank");
}

When It opens in the new window however, it opens slighty bigger than I had designed and of course the images become pixelated. The user can freely adjust the size as they please. So I was wondering how could I make it open to the exact size I designed (700X510) and keep it that size? Is there a simple way to specify this after "_blank"?

Thanks