PHP - Php Class Tutorial

I followed the tutorial at http://www.devshed.com/c/a/PHP/Building-An-Extensible-Form-Validator-Class/ because I wanted to have an easier way to build and maintain form validation.
I completed the tutorial, but the form does not register the form as being filled out.
Here is the class code (FormValidator.class.inc)
<?php
//FormValidator.class.inc
//class to perform form validation
class FormValidator {

   //---------------private variables------------------

   var $_errorList;
   //the _ prefix is used to distinguish private variables from public variables

   //---------------methods (private)------------------
   
   //functio to get the value of a variable (field)
   function _getValue($field) {
      global ${$field}; //makes the field entry a global variable
      return ${$field};
   }

   //---------------methods (public)-------------------
   
   //it is a good idea to run resetErrorList() whenever the class is first initialized
   //PHP makes it possible to automatically execute a specific function when a new instance of a class is spawned. This function is referred to as a "constructor" and must have the same name as the class.
   //reset error list
   function FormValidator() {
      $this->resetErrorList();
   }
   
   
      //begin basic validation routines
      
   //check whether input is empty
      //the isEmpty public method is called with 2 arguments, one for the form variable and one for the error message
      //the method internally calls the _getValue method and then trim()s the result to check if it is empty
      // if the variable is empty, a new element is added class variable $_errorList (an array) to represent the error. This new element is itself a three-element associative array, with the keys "field", "value" and "msg", representing the form variable name, the current value of that variable, and the corresponding error message
      // if the variable is not empty, it will pass the test and return true
      // this function, along with _getValue, allows the user to get both the field name and the field value
      //the $this prefix provides a convenient way to access variables and functions which are "local" to the class.
   function isEmpty($field, $msg) {
      $value = $this->_getValue($field);
      if (trim($value) == "") {
         $this->_errorList[] = array("field" => $field, "value" => $value, "msg" => $msg);
         return false;
      }
      else {
         return true;
      }
   }
   
   //check whether input is a string
   function isString($field, $msg) {
      $value = $this->_getValue($field);
      if(!is_string($value)) {
         $this->_errorList[] = array("field" => $field, "value" => $value, "msg" => $msg);
         return false;
      }
      else {
         return true;
      }
   }
   
   //check whether input is a number
   function isNumber($field, $msg) {
      $value = $this->_getValue($field);
      if(!is_numeric($value)) {
         $this->_errorList[] = array("field" => $field, "value" => $value, "msg" => $msg);
         return false;
      }
      else {
         return true;
      }
   }
   
   //check whether input is an integer
   function isInteger($field, $msg) {
      $value = $this->_getValue($field);
      if(!is_integer($value)) {
         $this->_errorList[] = array("field" => $field, "value" => $value, "msg" => $msg);
         return false;
      }
      else {
         return true;
      }
   }
   
   //check whether input is a float
   function isFloat($field, $msg) {
      $value = $this->_getValue($field);
      if(!is_float($value)) {
         $this->_errorList[] = array("field" => $field, "value" => $value, "msg" => $msg);
         return false;
      }
      else {
         return true;
      }
   }
   
   //check whether input is within a valid numeric range
   function isWithinRange($field, $msg, $min, $max) {
      $value = $this->_getValue($field);
      if(!is_numeric($value) || $value < $min || $value > $max) {
         $this->_errorList[] = array("field" => $field, "value" => $value, "msg" => $msg);
         return false;
      }
      else {
         return true;
      }
   }
   
   //check whether the input is alphanumeric
   function isAlpha($field, $msg) {
      $value = $this->_getValue($field);
      $pattern = "/^[a-zA-Z]+$/";
      if (preg_match($pattern, $value)) {
         return true;
      }
      else {
         $this->_errorList[] = array("field" => $field, "value" => $value, "msg" => $msg);
         return false;
      }
   }
   
   //check whether input is a valid email address
   function isEmailAddress($field, $msg) {
      $value = $this->_getValue($field);
      $pattern =
      "/^([a-zA-Z0-9])+([\.a-zA-Z0-9_-])*@([a-zA-Z0-9_-])+(\.[a-zA-Z0-9_-]+)+/
      ";
      if (preg_match($pattern, $value)) {
         return true;
      }
      else {
         $this->_errorList[] = array("field" => $field, "value" => $value, "msg" => $msg);
         return false;
      }
   }
   
      //end basic validation routines-----
   
   //return the list of current errors
   function getErrorList() {
      return $this->_errorList;
   }
   
   //check whether any errors have occured in validation
      //this method checks the size of the $_errorList array; if the size is greater than one, it implies that one or more errors have occured during validation
      //it returns a Boolean value
   function isError() {
      if(sizeof($this->_errorList) > 0) {
         return true;
      }
      else {
         return false;
      }
   }
   
   
   //reset the error list to a blank array
   function resetErrorList() {
      $this->_errorList = array();
   }

}//end FormValidator class
?>
-------Here is the form (simpleform.html)
<html>
   <head>
      <basefont face="Arial">
   </head>
   <body>
      <form action="processor.php" method="POST">
         <b>Name:</b>
            <br>
            <input type="text" name="name" size="15">
      
         <p>
      
         <b>Age:</b>
            <br>
            <input type="text" name="age" size="2" maxlength="2">
         
         <p>
      
         <b>Sex:</b>
            <br>
            <input type="Radio" name="sex" value="m">Male
            <input type="Radio" name="sex" value="f">Female
         
         <p>
      
         <b>Favourite sandwich type:</b>
            <br>
            <select name="stype">
               <option value="">-select one-</option>
               <option value="1">Thin crust</option>
               <option value="2">Thick crust</option>
               <option value="3">Toasted</option>
            </select>
         
         <p>

         <b>Favourite sandwich filling:</b>
            <br>
            <input type="Checkbox" name="sfill[]" value="BLT">Bacon, lettuce tomato
            <input type="Checkbox" name="sfill[]" value="EC">Egg and cheese
            <input type="Checkbox" name="sfill[]" value="PBJ">Peanut butter and jelly
         
         <p>
      
         <input type="Submit" name="submit" value="Save">
      
      </form>
   </body>
</html>
------and here is processor.php
<?php
//include class
include("FormValidator.class.inc");
// instantiate object
$fv = new FormValidator();
//perform validation
   $fv->isEmpty("name", "Please enter a name");
   $fv->isNumber("age", "Please enter a valid age");
   $fv->isWithinRange("age", "Please enter an age within the numeric range 1-99", 1, 99);
   $fv->isEmpty("sex", "Please enter your sex");
   $fv->isEmpty("stype", "Please select one of the listed sandwich types");
   $fv->isEmpty("sfill", "Please select one or more of the listed sandwich fillings");
   if($fv->isError()) {
      $errors = $fv->getErrorList();
      echo "<b>The operation could not be performed because one or more error(s) occurred.</b> <p> Please resubmit the form after making the following changes:";
      echo "<ul>";
         foreach($errors as $e) {
            echo "<li>" . $e['msg'] . "</li>";
         }
         echo "</ul>";
   }
   else {
      //do something useful with the data
      echo "Data OK";
   }

?>