<script language="php">

$result = "ok";
$type = "none";

// return to form page

function return_home()
{
   header( "Location: http://127.0.0.1        /registration/registrationSubmission.html" );
}

// cannot have blank name, city, or state

if( ( !$_POST[firstNameField] ) ||  ( !$_POST[lastNameField] ) || 
    ( !$_POST[cityField] ) || ( !$_POST[state] ) ) 
{
    // indicate that the above fields cannot be blank    
    $result = "error";
    $type = "name_city";

    return_home();  // yea, I know this a problem too
    exit;
}

// make sure the email address entered is the same in both places(and is not blank)
if ( ( $_POST[emailField]  ) && ( $_POST[confirmEmailField] ) )
{
   if ( strcmp( $_POST[emailField], $_POST[confirmEmailField] ) != 0 ) 
   {
        result = "error";
        type = "password_match";    
             
        return_home();
        exit;
    } 
    else 
    {
        
        return_home();
        exit;
    }
}

/* if there are no errors, write data to new record in the database */
.
.
.
</script> 

<?php
// check if some required user input was submitted
if( isset($_POST['firstNameField'])  &&  $_POST['firstNameField'] )
{
  // the rest

<?php
if( $_POST )
{ // the form was submitted.

    // TODO: Manage (remove) slashes in $_POST values if 'magic_quotes_gpc' is set ON
        
    $error_code = 1; // assume username field is empty already.
    if( isset($_POST['username'])  &&  $_POST['username']=trim($_POST['username']) )
    {
        $error_code = 2; // assume password fields are empty already.
        
        // TODO: verify correct lengths for username & password.
        
        if( isset($_POST['password'])  &&  $_POST['password']=trim($_POST['password']) )
        {
            if( isset($_POST['password2'])  &&  $_POST['password2']=trim($_POST['password2']) )
            {
                $error_code = 4; // assume passwords don't match already
                if( $_POST['password'] === $_POST['password2'] )
                {
                    // SUCCESS! Add script to insert this data into our DB.
                    // ...
                    
                    // Registration was a success, redirect to homepage, activation page or login page.
                    die( header("Location: http://www.example.com/") );     
                }
            }
        }
    }
    else
    {
        $_POST['username'] = null;    
    }
    echo markup_form( $_POST['username'], $error_code );
}
else
{
    echo markup_form();
}
// page markup ends here....
// -------------------------



// FUNCTIONS

/**
 * 
 * @access private
 * @param integer $error_code    The 3 main error codes.  1=>Empty Username Field, 2=>Empty Password Fields (one or both), 4=>Password Mismatch.
 * @return string The error message in <code>&lt;div&gt;</code> tags.
 */
function _markup_form_errors($error_code)
{
    $markup = '<div style="color:red; font-size:smaller;">';
    switch( $error_code )
    {
        case 1: // Empty username field
            $markup .= 'Please fill-in a username.  This data is required.';
            break;
        case 2: // Empty password fields
            $markup .= 'Please fill-in the same password in both the fields below.  This data is required.';
            break;
        case 4: // Password Mismatch
            $markup .= 'The passwords you submitted did not match.  Please try again.';
            break;
        default:
            $markup = null;
    }
    if( $markup )
        $markup .= '</div>';
    return $markup;    
}

/**
 * 
 * 
 * @param string $username The username supplied by the reader. Optional.
 * @param integer $error_code 3 main error codes.  See function <code>_markup_form_errors</code>. Optional.
 * @return string
 */
function markup_form( $username=null, $error_code=null )
{
    // The user supplied 'username' will be displayed in the form if
    // it was submitted but errors also exist e.g. mismatched passwords.
    if( !is_null($username) )
        $username = 'value="' . htmlspecialchars( $username ) . '" ';

    $error_message = ( $error_code ? _markup_form_errors($error_code) : null );
    
    return    "<form name=\"register\" id=\"formRegister\" action=\"$_SERVER[PHP_SELF]\" method=\"post\">\n" .
            "    <p>\n" .
            ( ($error_code & 1) ? "\t\t$error_message\n" : null ) .
            "        <label for=\"inputUsername\">\n" .
            "            <input type=\"text\" name=\"username\" id=\"inputUsername\" size=\"10\" maxlength=\"16\" $username/>\n" .
            "            Username\n" .
            "        </label>\n" .
            "    </p>\n" .
            "    <p>\n" .
            ( ($error_code & 4) ? "\t\t$error_message\n" : null ) .
            ( ($error_code & 2) ? "\t\t$error_message\n" : null ) .
            "        <label for=\"inputPassword\">\n" .
            "            <input type=\"password\" name=\"password\" id=\"inputPassword\" size=\"10\" maxlength=\"16\" />\n" .
            "            Password\n" .
            "        </label>\n" .
            "    </p>\n" .
            "    <p>\n" .
            "        <label for=\"inputPassword2\">\n" .
            "            <input type=\"password\" name=\"password2\" id=\"inputPassword2\" size=\"10\" maxlength=\"16\" />\n" .
            "            Re-type Password\n" .
            "        </label>\n" .
            "    </p>\n" .
            "    <p>\n" .
            "        <input type=\"submit\" name=\"register\" id=\"inputSubmit\" value=\"Register\" />\n" .
            "    </p>\n" .
            "</form>";
}
?>