Event.observe( window, 'load', function () {
  
  var active_color = '#000000';
  var inactive_color = '#7F7F7F';
  var default_text = 'Enter your email';
  
  var s = $('newsletter');
  
  s.setStyle({ color: inactive_color });
  s.value = default_text
  
  s.observe( 'focus', function () {

    s.value = '';
    s.setStyle({ color: active_color });

    s.observe( 'blur', function () {
      if (s.value == '') {
          s.setStyle({ color: inactive_color });
          s.value = default_text;
      }
    });
  });
});