[flexcoders] Help me understand restrict property

[markgoldin_2000]

Can someone please explain why the following code has no effect for a 
data entry into a textbox in the grids?
public class textItemRenderer extends TextInput
{
        public function textItemRenderer()
        {
        super();
        height = 20;
        restrict ="A-Z";
.....

var ConsistPersonnel1Name:ClassFactory = new ClassFactory
(textItemRenderer);
var consistPersonnel1Name:AdvancedDataGridColumn = PersonnelGrid.columns
[1];
consistPersonnel1Name.itemRenderer = ConsistPersonnel1Name;
I still can type any character.

Thanks