function openwin(url,w,h,scroll){
myname="";
LeftPosition = parseInt((screen.width) ? (screen.width-w)/2  : 0);
TopPosition = parseInt((screen.height) ? (screen.height-h)/2  : 0);
settings = 'height='+h+',width='+w+',top='+TopPosition+',left='+LeftPosition+',scrollbars='+scroll;
var wina = window.open(url,myname,settings);
wina.focus();
}