new window resizing HELP!

i have an imagemap, and i don't know where to write in the specific size for the new window popping up...if it's possible? i'm having just an "add to cart" page pop up and i don't need a big space...
thanks for any help!!!

<area shape="poly"#$36.95 decorated mixed
coords="590,313,431,309,430,325,565,334,581,315,581,313,581,313,581,313" href="b3695.html" title="$36.95 decorated mixed" target="_blank" />
<area shape="default" nohref="nohref" alt="" />
</map>

function doOpen(url, target, w, h){
var win = window.open(url, target, "width="+w+", height="+h);
win.focus();
return false;
}
...
<area ... href="b3695.html" target="_blank" onclick="return doOpen(this.href, this.target, 800, 600)" />