Javascript button makes residing window blank w/{object}

on (release) {
getURL ("javascript:NewWindow=window.open('In_America.html','photoWin','width=800,height=400,left=315,top=285,toolbar=No,location=No,scrollbars=No,status=No,resizable=Yes,fullscreen=No')");
NewWindow.focus();
void(0);
}

This code is attached to buttons in my main page opening different urls. They open great but, in some browsers the main page goes white with {object} in it and the viewer has to hit the back button to get thru to the main page again to click another link. I have been searching for two days but have found no examples of this happening with such simple javascript code. My site: www.josephkurtz.net. Any help would be really appreciated as i think the site is finished after this fix, thanks to this site and others.