[combo] [selected default value] [size]How to manage combo?

var FCKMyCombo_command = function(name) 
{
   this.Name = name ;

}

//This get's executed when an item from the combo list
FCKMyCombo_command.prototype.Execute = function (itemText, itemLabel)
{
   var oEditor = FCKeditorAPI.GetInstance('FCKeditor1');
   /*if (itemText != "")
      oEditor.InsertHtml(itemText);*/
}

FCKMyCombo_command.prototype.GetState = function() 
{
   return;
}

FCKCommands.RegisterCommand( 'mycombocommand' , new FCKMyCombo_command('mycombocommand') ) ;



/*
2nd, create the Combo object
*/
var FCKToolbarMyCombo = function(tooltip,style)
{
   
   this.Command = FCKCommands.GetCommand('mycombocommand');//the command to execute when an item is selected
   this.CommandName = 'mycombocommand';
   this.Label = this.GetLabel();
   this.Tooltip = tooltip? tooltip : this.Label; //Doesn't seem to work
   this.Style = style; //FCK_TOOLBARITEM_ICONTEXT OR FCK_TOOLBARITEM_ONLYTEXT
};

FCKToolbarMyCombo.prototype=new FCKToolbarSpecialCombo;


//NO Label to appear in the FCK toolbar
FCKToolbarMyCombo.prototype.GetLabel=function()
{
   return "";
};

//Add the items to the combo list
FCKToolbarMyCombo.prototype.CreateItems = function (A)
{
   //this._Combo.AddItem(itemText, itemLabel); //see FCKMyCombo_command.prototype.Execute = function(itemText, itemLabel) above
   //this._Combo.AddItem('catalán to insert', '<span style="color:#000000;font-weight: normal; font-size: 10pt;">catalán</span>');
   this._Combo.AddItem('català', 'català');
   this._Combo.AddItem('español', 'español');
   this._Combo.AddItem('english', 'english');
}

//Register the combo with the FCKEditor
FCKToolbarItems.RegisterItem( 'mycombo' , new FCKToolbarMyCombo( 'mycombo', FCK_TOOLBARITEM_ICONTEXT ) ) ; //or FCK_TOOLBARITEM_ONLYTEXT

function FCKeditor_OnComplete ( editorInstance )
 {
  // inic. toolbar
  editorInstance.Commands.GetCommand( 'mycombocommand' ).Execute('cat','català');