function Submit()
{
    
    // Validate data
    var error = false;
    if ( $F('location_text') == '' )
    {
        $('location').show();
        error = true;
    }
    else
        $('location').hide();
    
    if ( $F('contact_name_text') == '' )
    {
        $('contact_name').show();
        error = true;
    }
    else
        $('contact_name').hide();
    

    $('email').hide();
    $('email_invalid').hide();
    if ( $F('email_text') == '' )
    {
        $('email').show();
        error = true;
    }
    else if ( !(/^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/.test($F('email_text'))) )
    {
        $('email_invalid').show();
        error = true;
    }
    
    
    if ( $F('phone_text') == '' )
    {
        $('phone').show();
        error = true;
    }
    else
        $('phone').hide();
    
    if ( $F('message_text') == '' )
    {
        $('message').show();
        error = true;
    }
    else
        $('message').hide();

    
    if ( error )
        return false;
    else
    {
        // Send message
        new Ajax.Request('/send.php',
            {
                method: 'post',
                parameters:
                {
                    location:     $F('location_text'),
                    contact_name: $F('contact_name_text'),
                    email:        $F('email_text'),
                    phone:        $F('phone_text'),
                    event_date:   $F('event_date_text'),
                    event_time:   $F('event_time_text'),
                    message:      $F('message_text')
                },
                onSuccess: function(transport)
                {
                    alert(transport.responseText);
                }
            }
        );
    }
}