Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/10/17/disabling-an-alert-control-in-flex/ -->
<mx:Application name="Alert_enabled_test"
        xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            import mx.controls.Alert;
            import mx.managers.PopUpManager;

            private const ENABLE_DELAY:uint = 3000; // 3 seconds

            private var a:Alert;

            private function showAlert():void {
                a = Alert.show("You have been logged out.", "Goodbye");
                a.enabled = false;
                setTimeout(enableAlert, ENABLE_DELAY, a);
            }

            private function enableAlert(target:Alert):void {
                target.enabled = true;
                // PopUpManager.removePopUp(target);
            }
        ]]>
    </mx:Script>

    <mx:Button id="button"
            label="Logout"
            click="showAlert();" />

</mx:Application>

View source is enabled in the following example.

Update (10/18/2007): If you don’t want to disable the entire Alert control, you can loop over the internal button array and disable each of the button controls individually, as seen in the following example:

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/10/17/disabling-an-alert-control-in-flex/ -->
<mx:Application name="Alert_enabled_test"
        xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            import mx.events.FlexEvent;
            import mx.utils.ObjectUtil;
            import mx.controls.Alert;
            import mx.managers.PopUpManager;

            private const ENABLE_DELAY:uint = 3000; // 3 seconds

            private var a:Alert;

            private function showAlert():void {
                a = Alert.show("You have been logged out.", "Goodbye");
                toggleButtons(a, false);
                setTimeout(enableAlert, ENABLE_DELAY, a);
            }

            private function enableAlert(target:Alert):void {
                toggleButtons(target, true);
            }

            private function toggleButtons(target:Alert, isEnabled:Boolean):void {
                var buttonArr:Array = target.mx_internal::alertForm.mx_internal::buttons;
                var btn:Button;
                for each (btn in buttonArr) {
                    btn.enabled = isEnabled;
                }
            }
        ]]>
    </mx:Script>

    <mx:Button id="button"
            label="Logout"
            click="showAlert();" />

</mx:Application>

Since this example uses the mx_internal namespace, you can’t always depend on this behavior to work in future versions of the Flex SDK. Use at your own risk.

 

Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/01/27/displaying-a-textinput-controls-text-as-a-password-in-flex-redux/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            import mx.controls.Alert;
            import mx.managers.PopUpManager;

            private var alert:Alert;

            private function submit_click():void {
                alert = Alert.show("Closing in 3 seconds.",
                                    "Submitting...");
                setTimeout(closeAlert, 3000);
            }

            private function reset_click():void {
                alert = Alert.show("Closing in 1 second.",
                                    "Resetting...");
                username.text = "";
                password.text = "";
                setTimeout(closeAlert, 1000);
            }

            private function closeAlert():void {
                PopUpManager.removePopUp(alert);
            }
        ]]>
    </mx:Script>

    <mx:Panel title="Login">
        <mx:Form>
            <mx:FormItem label="Username:" required="true">
                <mx:TextInput id="username"
                        text="JohnDoe"
                        maxChars="16" />
            </mx:FormItem>
            <mx:FormItem label="Password:" required="true">
                <mx:TextInput id="password"
                        text="p455w0rd"
                        maxChars="16"
                        displayAsPassword="true"
                        focusIn="password.displayAsPassword = false;"
                        focusOut="password.displayAsPassword = true;" />
            </mx:FormItem>
        </mx:Form>
        <mx:ControlBar horizontalAlign="right">
            <mx:Button id="submit"
                    label="Submit"
                    click="submit_click();" />
            <mx:Button id="reset"
                    label="Reset"
                    click="reset_click();" />
        </mx:ControlBar>
    </mx:Panel>

</mx:Application>

View source is enabled in the following example.

 

Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/10/22/programmatically-removing-an-alert-using-the-popupmanager/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            import mx.controls.Alert;
            import mx.managers.PopUpManager;

            private var alert:Alert;

            private function showAndHide(delay:Number):void {
                var alertText:String = "I'm an Alert control. I'll disappear in " + (delay / 1000).toFixed(1) + " seconds.";
                var alertTitle:String = "Timed Alert";
                alert = Alert.show(alertText, alertTitle);
                setTimeout(hideAlert, delay);
            }

            private function hideAlert():void {
                PopUpManager.removePopUp(alert);
            }
        ]]>
    </mx:Script>

    <mx:ApplicationControlBar dock="true">
        <mx:Button label="Launch alert"
                click="showAndHide(3000);" />
    </mx:ApplicationControlBar>

</mx:Application>

View source is enabled in the following example.