var msContentButton = Class.create(msButton, {
  xtype: 'content-button',
   
  //a reference to the custom content will be drawn
  viewer: false,

  // redefine the constructor
  initialize: function ($super,config) {
    $super(config);
    
    if(!this.viewer) {
      Object.extend(this, { viewer: eval(this.config.viewer) });
    }   
  },
 
  // redefine the build method
  build: function ($super) {      
    
    this.el = new Element('div');
    this.el.id = this.config.id;
  },
  
  getWidthForState: function(state) {
    return 600;
  }
});