[flexcoders] horizontalAxisRenderer VS horizontalAxisRenderers?

[sailorsea21]

Hi everyone, 
I have the following script:
 
var columnChart:ColumnChart                 = new ColumnChart();
var axisVRenderer:AxisRenderer              = new AxisRenderer();
        axisVRenderer.placement             = "left";
        axisVRenderer.axis                  = int_20;
        axisVRenderer.labelFunction         = axisPercent;
        ***columnChart.verticalAxisRenderers   = axisVRenderer; 

I don't understand why it's generating the following error:

***
1067: Implicit coercion of a value of type mx.charts:AxisRenderer to an 
unrelated type Array.

If I replace the verticalAxisRenderers by verticalAxisRenderer I receive the 
following warning:

3606: 'verticalAxisRenderer' has been deprecated.  Please use 
'CartesianChart.verticalAxisRenderers'.

Should I use verticalAxisRenderer and ignore the warning?

Thanks.

-David