function checkform (form) {
 
   var r=0;
   var message = "Before submiting a comment please provide:\n";
 

if (form.name.value=="") {
     message += "\n- Your name";
     r++;
}

if (form.location.value=="") {
     message += "\n- Your location";
     r++;
}

if (form.message1.value=="") {
     message += "\n- Your comment";
     r++;
}

if (form.code.value=="") {
     message += "\n- Your verification code";
     r++;
}


 if (r > 0) {
  alert(message);
     return false;
 }
 else{
  return true;
 }
 
 
}