function openwindow(url_address,window_width,window_height,framename,additional,is_picture) {
sx = (screen.availWidth - window_width) / 2;
sy = (screen.availHeight - window_height) / 2;
params = "width="+window_width+",height="+window_height+",Left="+sx+",Top="+sy+",screenX="+sx+",screenY="+sy;
if(additional>"") params += "," + additional;
nw = window.open(url_address, framename, params);
if(is_picture) {
nw.document.open();
nw.document.write("Booking.hu - Photos\n");
nw.document.write("\n");
nw.document.write("![photo]("+url_address+")
\n");
nw.document.write("\n");
nw.document.write("\n");
nw.document.close();
}
nw.focus();
}