function clearField(field) {
  if (field.value == field.defaultValue) 
    field.value = "";
}

function checkField(field) {
  if (field.value == "") 
    field.value = field.defaultValue;
}

nn4=(document.layers) ? true : false; 
ie4=(document.all) ? true : false; 

Nowe=null; 
function otworz(src,w,s) { 
srodekX=screen.width/2-s/2;
srodekY=screen.height/2-w/2;
if (Nowe) { 
 if (ie4) Nowe.close(); 
 else if (nn4) Nowe.closed; 
 Nowe=null;
 }; 
Nowe=window.open(src,'','toolbar=no,menubar=no,location=no,personalbar=no,scrollbars=no,status=no,directories=no,resizable=no,top='+srodekY+',left='+srodekX+',height='+w+',width='+s);
Nowe.focus();
}