<?xml version="1.0" encoding="utf-8"?>
  <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
  
          <mx:Script>
                  <![CDATA[
                          import mx.controls.TextInput;
                          import mx.events.DataGridEvent;
                          import mx.collections.ArrayCollection;
                          
                          [Bindable]
                          private var productsAC:ArrayCollection = new ArrayCollection
                          (
                                  [
                                          {Product: "iPod", Price: 249},
                                          {Product: "iMac", Price: 1299},
                                          {Product: "MacBook Pro", Price: 1999}
                                  ]
                          );
                          
                          private function onEditBeginning(event:DataGridEvent):void
                          {
                                  if (event.rowIndex == 2)
                                          event.preventDefault();
                          }
                          
                  ]]>
          </mx:Script>
          
          <mx:DataGrid dataProvider="{productsAC}" editable="true" itemEditBeginning="onEditBeginning(event)">
                  <mx:columns>
                          <mx:DataGridColumn dataField="Product" />
                          <mx:DataGridColumn dataField="Price" />
                  </mx:columns>
          </mx:DataGrid>
          
  </mx:Application>