[flexcoders] ItemEditor | maxCharacters

[ilikeflex]

Hi

I have datagrid and i am using the default itemeditor. I want to limit the 
charatcres the user can enter.

I have implemented itemEditBegin method on datagrid.

private function onitemEditBegin(event:DataGridEvent):void
{
        var datGrid:CheckBoxDataGrid=(event.currentTarget as CheckBoxDataGrid);
        var customDataGridColumn:CustomDataGridColumn = 
datGrid.columns[event.columnIndex] as CustomDataGridColumn;
        var field:String=datGrid.columns[event.columnIndex].dataField;
        if(field == "prlName")
        {
                var editor:TextInput = datGrid.itemEditorInstance as TextInput;
                editor.maxChars = 5;
        }

}

I always get editor as null... so i am not able to set maxChars on TextInput. 
How to do this..

Any pointers.

Thanks
ilikeflex