Pop Up centered Window problem

1

i got this button my code is like this

on (release) {
getURL(“http://sucasahogar.com/mensaje.html”, “_blank”);
}

but the problem is that the content of this link is just 300x260
so I dont need the the big browser to be displayed on this litle form

go can go to this link if you want to se what Im talking about

[COLOR=#22229c]http://sucasahogar.com/mensaje.html[/COLOR]

my question is… if there are a code the just to be dispalay the mesasurements of my file