It works but I don't know why ... could someone help me

Hi Folks

Maby this question sounds stupid, but I managed to define my own Plug-In, but I don't really know why it works.
So that in the future I may be more sure about the fckEditor, maybe somebody may explain what I have done.

The target was to create a Toolbar-Button what inserts some HTML:

<table cellspacing="0" cellpadding="0" border="0" background="/pix/content_trennlinie.gif" width="100%"><tr>
<td valing="top"><img height="25" border="0" width="100%" src="/pix/0.gif" alt="" /></td>
</tr></table>

So I defined I Toolbar Button 'InsertHrTable' in the fckConfig.js:

FCKConfig.ToolbarSets["Default"] = [
   ['FitWindow','Source','-','-','Preview'],
   ['Cut','Copy','Paste','PasteText','PasteWord','-','Print'],
   ['Undo','Redo','-','Find','Replace','-','SelectAll','RemoveFormat'],
   '/',
   ['OrderedList','UnorderedList','-','Outdent','Indent'],
   ['JustifyLeft','JustifyCenter','JustifyRight','JustifyFull'],
   ['Link','Unlink','Anchor'],
   ['Image','Flash','Table','Rule','InsertHrTable','Smiley','SpecialChar'],
   '/',
   ['Style','FontFormat','-','Bold','Italic','Underline','StrikeThrough','-','Subscript','Superscript'],
   ['TextColor','BGColor'],
   ['ShowBlocks']
];

and added the plugin

FCKConfig.Plugins.Add( 'InsertHrTable', 'de,en' );

after this I created the directory "InsertHrTable" in the Plugins-Folder and created the "fckplugin.js".
All above is not a problem. I even managed some Plugins wich open a popup an return some content, but I never made just a button what does not interact with the user. So the code from here makes me unsure, even if it works, since I would like to understand it :

// Define the command.
var FCKInsertHrTable = function() {
   this.name = 'InsertHrTable';
}

FCKInsertHrTable.prototype ={
   Execute:function() {
      FCKUndo.SaveUndoStep();
      FCK.InsertHtml('<table cellspacing="0" cellpadding="0" border="0" background="/pix/content_trennlinie.gif" width="100%"><tr><td valing="top"><img height="25" border="0" width="100%" src="/pix/0.gif" alt="" /></td></tr></table>') ;
   }, GetState:function() {
      if (FCK.EditMode!=0) return -1;
      return FCK.GetNamedCommandState('InsertHrTable');
   }
}

// Register the HrTable tag command.
FCKCommands.RegisterCommand( 'InsertHrTable', new FCKInsertHrTable() ) ;

// Create the 'InsertHrTable' toolbar button. 
// FCKToolbarButton takes the following arguments: CommandName, Button Caption 
var oInsertHrTable = new FCKToolbarButton( 'InsertHrTable', FCKLang['DlgInsertHrLineBtn'] ) ; 
oInsertHrTable.IconPath = FCKPlugins.Items['InsertHrTable'].Path + 'icon.gif' ; 
FCKToolbarItems.RegisterItem( 'InsertHrTable', oInsertHrTable ) ;



//var FCKRuleCommand=function(){
//   this.Name='Rule';
//};

//FCKRuleCommand.prototype={
//   Execute:function(){
//      FCKUndo.SaveUndoStep();
//      FCK.InsertElement('hr');
//   },GetState:function(){
//      if (FCK.EditMode!=0) return -1;
//      return FCK.GetNamedCommandState('InsertHorizontalRule');
//   }
//};

As you can see, I did search the original Rule function from "fckeditor_gecko.js" (the code with the remarks) and builded my function with some other examples togeter.
My questions beginn with the var "FCKInsertHrTable".

var FCKInsertHrTable = function() {
   this.name = 'InsertHrTable';
}

and the Register Command

FCKCommands.RegisterCommand( 'InsertHrTable', new FCKInsertHrTable() ) ;

What excatly does the first parameter from RegisterCommand represent, the Toobar-Placeholder?
And what is allowed for the second Parameter?
In this case I do "understand" in a simple way, that the Instance of FCKInsertHrTable is used.
But I don't see out of the documentation if even some arguments are given to my FCKInserHrTable function.
And don't know, what this statement means and what effects it has:

this.name = 'InsertHrTable';

The next question is about:

FCKInsertHrTable.prototype ={
   Execute:function() {
      FCKUndo.SaveUndoStep();
      FCK.InsertHtml('<table cellspacing="0" cellpadding="0" border="0" background="/pix/content_trennlinie.gif" width="100%"><tr><td valing="top"><img height="25" border="0" width="100%" src="/pix/0.gif" alt="" /></td></tr></table>') ;
   }, GetState:function() {
      if (FCK.EditMode!=0) return -1;
      return FCK.GetNamedCommandState('InsertHrTable');
   }
}

In my opinion, fckeditor allwase uses the Execute command. If I understand it right, this function will be executet on Click on the toolbar icon.
But whatfor is "GetState" and what other default function do exist.
I was looking for some documentation, what the diffrent functions are doing and what arguments they get, but I didn't find anything like it.

The FCKUndo.SaveUndoStep() and FCK.InsertHtml are clear for me.

But since I copied the source out of "fckeditor_gecko.js" I'm not sure if the function will work with the other Browsers.

maybe somebody can enlight me
sorry for the terrible english

For any explenation thanks