Unfortunately, placeholders don’t run versions of IE9 and down.

But we can solve this problem easily is a small jQuery code:

if( $.browser.msie && parseInt($.browser.version, 10) < 10 ) {
  if( $( '[placeholder]' ).length ) {
    $( '[placeholder]' ).focus(function(){
      if( $(this).val() == $(this).attr('placeholder') ) { $(this).val(''); }
    }).blur(function(){
      if( $(this).val() == '' ) { $(this).val( $(this).attr('placeholder') ); }
    }).blur();
  }
}

Have fun :)