var popupWindow = null;

function popup(url,width,height) {

 if(popupWindow!=null)
  {
  if (typeof(popupWindow) == "object")
   popupWindow.close();
//   popupWindow = null;
  }
        var width=width+18;
        var height=height;
        var top  = (screen.height - height) / 2;
        var left = (screen.width  - width)  / 2;
        $popup='popup'+width+'x'+height;
    popupWindow = window.open(url,$popup,'toolbar=no,menubar=no,scrollbars=yes,resize=no,titlebar=no,resizable=no,width='+width+',height='+height+',top='+top+',left='+left+'');
        popupWindow.focus();
}

function show(el,num)
 {
   document.getElementById('m'+el).src=images[num].src;
 }
function hide(el,num)
{
  document.getElementById('m'+el).src=im_names[num];
}

function fmenua(el)
 {
   document.getElementById('bg'+el).className='menua';
 }
function fmenu(el)
{
   document.getElementById('bg'+el).className='';
}