Problems implementing Plugin.

Hello,
I have the following in videogallery/fckplugin.js page

window.open(FCKConfig.PluginsPath + 'videogallery/showcase.html');
FCKCommands.RegisterCommand( 'videogallery' ,     new FCKDialogCommand( "ShowCase" , "ShowCase" , FCKConfig.PluginsPath + 'videogallery/showcase.html' , 500, 300 ) ) ;

var oFindItem = new FCKToolbarButton( 'videogallery', "ShowCase" ) ;
oFindItem.IconPath = FCKConfig.PluginsPath + 'videogallery/images.jpg' ;

FCKToolbarItems.RegisterItem( 'videogallery', oFindItem ) ; // 'My_Find' is the name used in the Toolbar config.

The following in fckconfig.jsp

FCKConfig.ToolbarSets["liferay"] = [
...
   ['Image','Flash','Table','-','Smiley','SpecialChar','videogallery']
] ;
...
FCKConfig.Plugins.Add('videogallery', 'es', sOtherPluginPath ) ;

The icon apears in the menu bar, but when I click it, a modal window opens with the title "ShowCase" and the loading bar.
But that is it. I never see the contents of showcase.html.

I added the window.open to make sure that the path is correct, and it is, the html page loads.

So what did I miss? what do I need to do so that the HTML is loaded in the modal window?

Another question. Once I manage to show the HTML, the person is going to be able to place some text.
How do I add that text to the HTML editor as source?

Thanks