function checkFields(f,fieldStr) {
  var fields = fieldStr.split(",");
  var message = "";
    for (i=0; i<fields.length; i++) {
      var theStr = f.elements[fields[i]].value;
      var trimmedStr = theStr.replace(/^\s+|\s+$/g,"")
    
      if (trimmedStr == '') {
        message = "All fields marked with an * must be completed";
      }
    }
    if (message != '') {
      alert(message);
      return false;
    }
    else {
      return true;
    }
}