Flash - radio button en Flex

<?xml version="1.0" encoding="utf-8"?>

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"

layout="absolute" creationComplete="users.send()"

color="#000101" backgroundGradientAlphas="[0.48, 1.0]"

backgroundGradientColors="[#C1C3C9, #103CF9]" cornerRadius="8"

alpha="1.0" borderStyle="solid" borderColor="#ED7F08"

themeColor="#FFFC00">

<mx:HTTPService id="users" url="http://localhost/proyecto1/conexion.php"

resultFormat="e4x"/>

<mx:HTTPService id="userLogin" url="flex.php"

                  useProxy="false"

  	              method="POST" result="getLoginResult(event)" fault="opciones(event.currentTarget.selectedValue)">

       <mx:request xmlns="">

        <dusuario> {dusuario.text} </dusuario>

        <dclave>   {dclave.text}   </dclave>

        <usu>      {usu.text}      </usu>

        <dnivel>   {dnivel.text}   </dnivel>

      </mx:request>

  </mx:HTTPService>

   <mx:Script>

      <![CDATA[

         public function rtn_mayus():void

         {usu.text = usu.text.toUpperCase();}

      ]]>

   </mx:Script>

  <mx:Script>

     <![CDATA[

      import mx.controls.ProgressBar;

      import mx.charts.chartClasses.DualStyleObject;

      import mx.collections.XMLListCollection;

      import mx.collections.ArrayCollection;

      import mx.rpc.events.ResultEvent;

      import mx.managers.PopUpManager;

      import mx.containers.TitleWindow;

      import mx.containers.ApplicationControlBar;

      import mx.controls.ToolTip;

      import mx.controls.Alert;

      import  mx.events.ItemClickEvent;

      [Bindable]

      private var loginResult : String;

      public var opcion:String;

      public function getLoginResult(event : ResultEvent) : void{

      loginResult = event.result.login;

         Alert.show(loginResult, "Estatus");

      }

      public function opciones(event:ItemClickEvent):void {

            if(event.currentTarget.selectedValue == "al")

            { opcion = event.currentTarget.selectedValue;

              //Alert.show("Seleccionaste el alta "+ opcion); 

            }

            else

             { if(event.currentTarget.selectedValue == "ba")

                {

                  //Alert.show("Seleccionaste la baja") 

                }

                else {

                    Alert.show("Seleccionaste modificar")

                }

            }

        }

   ]]>

   </mx:Script>

<mx:WipeUp id="wipeOut" duration="1000"/>

<mx:WipeUp id="wipeIn" duration="1000"/>

 <mx:TabNavigator x="23" y="10" width="358" height="320" id="uno">

  <mx:Canvas width="100%" height="100%" label="Consulta" cornerRadius="20" borderColor="#0D11B3" borderStyle="solid" backgroundColor="#C2B8B8" themeColor="#6A70E6" fontFamily="Arial" fontSize="12" borderThickness="4">

   <mx:DataGrid dataProvider="{users.lastResult..persona}" width="308" fontFamily="Times New Roman" fontSize="11" borderStyle="solid" borderColor="#010004" alternatingItemColors="[#B7B9BE, #FFFFFF]" themeColor="#F5ED72" x="10" y="80">

     <mx:columns>

       <mx:DataGridColumn headerText="USUARIO" dataField="usuario" width="65" textAlign="center"/>

       <mx:DataGridColumn headerText="NOMBRE" dataField="nombre"/>

     </mx:columns>

   </mx:DataGrid>

   <mx:Label text="Huesario's and Yonke's" fontFamily="Arial" fontSize="14" textAlign="center" enabled="true" x="10" y="18"/>

   <mx:Label text="Mantenimiento de usuarios" fontFamily="Arial" alpha="1.0" x="55" y="53"/>

   <mx:Image source="images/loldcar.gif" width="131" height="85" scaleContent="true" autoLoad="true" x="215" y="18"/>

  </mx:Canvas>

  <mx:Canvas label="Mantenimiento" width="100%" height="100%" fontFamily="Arial" fontSize="12" borderStyle="solid" borderColor="#000100" backgroundColor="#EB961C" borderThickness="4" themeColor="#5517A2" cornerRadius="20" alpha="1.0" backgroundAlpha="1.0">

   <mx:Label text="Huesario's and Yonke's" fontFamily="Arial" fontSize="14" textAlign="center" enabled="true" x="10" y="18"/>

   <mx:Image source="images/loldcar.gif" width="131" height="85" scaleContent="true" autoLoad="true" x="215" y="18"/>

   <mx:Label x="8" y="65" text="Usuario :"/>

   <mx:Label x="21" y="94" text="Clave :"/>

   <mx:Label x="7" y="123" text="Nombre :"/>

   <mx:Label x="25" y="152" text="Nivel :"/>

   <mx:TextInput x="81" y="65" id="dusuario" width="74" height="21" maxChars="8" backgroundAlpha="1.0" backgroundColor="#F9F600" borderStyle="solid" textAlign="center" borderThickness="2" cornerRadius="5" alpha="1.0" editable="true" enabled="true" borderColor="#4CA9F0" themeColor="#030105"/>

   <mx:TextInput x="81" y="94" id="dclave"   width="74" height="21" maxChars="8" backgroundAlpha="1.0" backgroundColor="#F9F600" borderStyle="solid" textAlign="center" borderThickness="2" cornerRadius="5" alpha="1.0" editable="true" enabled="true" borderColor="#4CA9F0" themeColor="#030105" displayAsPassword="true"/>

   <mx:TextInput change="rtn_mayus()" id="usu" x="81" y="123" width="233" height="21" maxChars="55" backgroundAlpha="1.0" backgroundColor="#F9F600" borderStyle="solid" textAlign="left" borderThickness="2" cornerRadius="5" alpha="1.0" editable="true" enabled="true" borderColor="#4CA9F0" themeColor="#030105"/>

   <mx:TextInput x="81" y="152" id="dnivel" width="36" height="21" maxChars="2" backgroundAlpha="1.0" backgroundColor="#F9F600" borderStyle="solid" textAlign="center" borderThickness="2" cornerRadius="5" alpha="1.0" editable="true" enabled="true" borderColor="#4CA9F0" themeColor="#030105"/>

   <mx:Button x="25" y="205" label="Enviar" click="userLogin.send();" fontWeight="bold" borderColor="#B7BABC" cornerRadius="7" alpha="0.6"/>

   <mx:Button x="94" y="205" label="Limpiar" alpha="0.6" cornerRadius="7"/>

   <mx:RadioButtonGroup id="type" itemClick="opciones(event);"/>

   <mx:RadioButton groupName="type" id="alta" value="al" label="alta" width="45" x="125" y="152"/>

   <mx:RadioButton groupName="type" id="baja" value="ba" label="baja" width="53" x="178" y="152"/>

   <mx:RadioButton groupName="type" id="modifica" value="mo" label="modifica" width="75" x="239" y="152"/>

  </mx:Canvas>

  <mx:Canvas label="efectos" width="100%" height="100%">

    <mx:Panel title="WipeUp Effect Example" width="95%" height="95%"

        paddingTop="5" paddingLeft="10" paddingRight="10" paddingBottom="5">

        <mx:Text width="100%" color="blue"

            text="Use the WipeUp effect to show or hide the text and image."/>

        <mx:Label text="Nokia 9930"

            fontSize="14"

            visible="{cb1.selected}"

            hideEffect="{wipeOut}" showEffect="{wipeIn}"/>

        <mx:Image source="@Embed(source='images/loldcar.gif')"

            visible="{cb1.selected}"

            hideEffect="{wipeOut}" showEffect="{wipeIn}"/>

        <mx:CheckBox id="cb1" label="visible" selected="true"/>

    </mx:Panel>

  </mx:Canvas>

 </mx:TabNavigator>

</mx:Application>

<?php

   $dusuario = "null";

   $dclave   = "null";

   $usu      = "null";

   $dnivel   = "null";

   $opcion   = "null";

   if (isset($_POST['dusuario']) &&

       isset($_POST['dclave'])   &&

       isset($_POST['usu'])      &&

       isset($_POST['dnivel']))

   {

     $dusuario = $_POST['dusuario'];

     $dclave   = $_POST['dclave'];

     $usu      = $_POST['usu'];

     $dnivel   = $_POST['dnivel'];

     $opcion   = $_POST['opcion'];

   }

   $Return = "<login>";

   $Return .= sprintf("Acceso correcto: %s - %s - %s - %s - %s",

                                                 $dusuario,

                                                 $dclave,

                                                 $usu,

                                                 $dnivel,

                                                 $opcion);

   $Return .= "</login>";

   print $Return;

?>