function VATtest() {
  a = document.editform.billing_country;
  vats = new Array('BE','DE','DK','GR','ES','FI','FR','IE','IT','LU','NL','PT','SE');
  for(i=0;i<=vats.length;i++){
   b=vats[i];
   if(b==a.value){
    document.editform.vatnumber.disabled=false;
   }
  }
}