FCKeditorAPI GetHTML not working in FF

var oEditor = FCKeditorAPI.GetInstance('FCKeditor1');
alert(oEditor.GetHTML());

include("fckeditor/fckeditor.php") ;
$oFCKeditor = new FCKeditor('FCKeditor1') ;
$oFCKeditor->Value      = '<p>This is some <strong>sample text</strong>. You are using <a href="http://www.fckeditor.net/">FCKeditor</a>.</p>' ;
$oFCKeditor->Height    = '450px';
$oFCKeditor->Create() ;