Ext.grid.CheckColumn = function(config){
    Ext.apply(this, config);
    if(!this.id){
        this.id = Ext.id();
    }
    this.renderer = this.renderer.createDelegate(this);
};

Ext.grid.CheckColumn.prototype ={
  init : function(grid){
    this.grid = grid;
    this.grid.on('render', function(){
        var view = this.grid.getView();
        view.mainBody.on('mousedown', this.onMouseDown, this);
    }, this);
  },

  onMouseDown : function(e, t){
    if(t.className && t.className.indexOf('x-grid3-cc-'+this.id) != -1){
      e.stopEvent();
      var index = this.grid.getView().findRowIndex(t);
      var record = this.grid.store.getAt(index);
      record.set(this.dataIndex, !record.data[this.dataIndex]);
    }
  },
  renderer : function(v, p, record){
    p.css += ' x-grid3-check-col-td';
    return '<div class="x-grid3-check-col'+(v?'-on':'')+' x-grid3-cc-'+this.id+'">&#160;</div>';
  }
};