var win = null; 

function NewWindow(mypage,myname,w,h,scroll){ 

  LeftPosition = (screen.width) ? (screen.width-w)/2 : 0; 

  TopPosition = (screen.height) ? (screen.height-h)/2 : 0; 

  settings ='height='+h+',width='+w+',top='+TopPosition+',
left='+LeftPosition+',scrollbars='+scroll+',resizable' 

  win = window.open(mypage,myname,settings) 

   if(win.window.focus){ 

      win.window.focus(); 

   } 

}