The navigateToURL influences the Alert PopUp behavior

Question

Hello all!
  Working on my project in Flex 4 Prem I've met the strange
model of behavior when I call navigateToURL method after creating
Alert popup window: being run the program does not wait user's mouse
click on OK button on Alert popup. Instead it displays the popup for
a sec and go to the next statement in source code: navigateToURL()
function's call.
  If I comment this navigateToURL() call, the program's behave returns
to normal as it is suppose to be: it waits until user clicks on the OK
button on the Alert popup window. The simple model of the source code
you can se below.
Please, help me to understand what I've done wrong.
Thanks a lot in advance!
Andrey Suntsev
The code:
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
               xmlns:s="library://ns.adobe.com/flex/spark"
               xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600">
    <s:layout>
       <s:BasicLayout/>
    </s:layout>
    <fx:Script>
        <![CDATA[
        import mx.controls.Alert;
        import mx.core.FlexGlobals;
        private function show_Messages(_event:MouseEvent):void
            Alert.show("Click OK");
            navigateToURL(new URLRequest(FlexGlobals.topLevelApplication.url), '_self');
        ]]>
    </fx:Script>
    <s:Button id="submitButton"
              label="Show message"
              click="show_Messages(event);" />
</s:Application>

Answer 1

@Uasav,
Something like this should work:
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark">
    <fx:Script>
        <![CDATA[
            import mx.controls.Alert;
            import mx.core.FlexGlobals;
            import mx.events.CloseEvent;
            protected function show_Messages(evt:MouseEvent):void  {
                Alert.show("Click OK", "", Alert.OK|Alert.CANCEL, null, alert_closeHandler);
            protected function alert_closeHandler(evt:CloseEvent):void {
                switch (evt.detail) {
                    case Alert.OK:
                        navigateToURL(new URLRequest(FlexGlobals.topLevelApplication.url), '_self');
                        break;
                    case Alert.CANCEL:
                        // ignore
                        break;
        ]]>
    </fx:Script>
    <s:Button id="submitButton"
              label="Show message"
              click="show_Messages(event);" />
</s:Application>
Peter