function popupSized(theURL, wname, width, height){
    positionx=(screen.width/2)-(width/2)
    positiony=(screen.height/2)-(height/2)
 window.open(theURL, wname,"width="+ width +",height="+ height +",resizable=yes,status=no,scrollbars=yes,toolbar=no,menubar=no,left=" + positionx + ",top=" + positiony + ",screenX=" + positionx + ",screenY=" + positiony);
}

function showhide(add_fields){
  if(document.getElementById(add_fields).style.display=='none') 
   document.getElementById(add_fields).style.display='block'; 
  else document.getElementById(add_fields).style.display='none';
}