code: function(value)
  	{
  		if(this._dataTipFunction)
  		{
  			YAHOO.widget.Chart.removeProxyFunction(this._dataTipFunction);
  		}
  		
  		if(value)
  		{
  			this._dataTipFunction = value = YAHOO.widget.Chart.getFunctionReference(value);
  		}
  		this._swf.setDataTipFunction(value);
  	}
docs: Setter for the dataTipFunction attribute.
  
  @method _setDataTipFunction
  @private