Html pop-up window

Im trying to make it so when i click a button a new window pops up with the new html page, i also need it to be specific dementions but i dont know how to do this. heres what i have so far

on (release) {
getURL(www.comboclothing.com/program.htm, “_blank”);

}

which by the way doesnt even work, it sends me to comboclothing.com/NaN ( which is a page i dont even have. any help?