function showmenu(id)
{
		document.getElementById(id).style.visibility  = 'visible';

}

function hidemenu(id)
{
		document.getElementById(id).style.visibility  = 'hidden';
}

function _popup(href,w,h,name,scrollbars){
  var width=screen.availWidth;
  var height=screen.availHeight;
  var props='';
  
  var left=width<w?0:(width-w)/2;
  var top=height<h?0:(height-h)/2;
  props='scrollbars='+(scrollbars ? '1' : '0')+',directories=0,menubar=0,status=0,toolbar=0,resizable=0,location=0,left='+left+',top='+top+',height='+h+',width='+w;
  var win=window.open(href,name,props);
  win.focus();
  return false;
}