Keyboard-focus on Texbox in ActionScript - actionscript-3

Question

I made a login form on Flex and set the focus on the first textbox.
The textbox is highlighted, but I have to click on it in order to be able to write inside it.
How can I make it takes keyboard input directly without clicking? I mean directly after loading the page.
<fx:Script>
<![CDATA[
private function init():void {
trace("Authentication View init");
ExternalInterface.call('function browserFocus(){document.getElementById(\'${application}\').focus();}');
this.txtUsername.setFocus();
this.txtUsername.setFocus();
}
]]>
</fx:Script>
<s:Panel x="353" y="164" width="250" height="200">
<s:TextInput id="txtUsername" x="103" y="49" focusEnabled="true"/>
<s:TextInput x="103" y="79"/>
<s:Label x="26" y="49" text="Username"/>
<s:Label x="26" y="79" text="Password"/>
</s:Panel>

Answer 1

Set focus like following inside init() function.
txtUsername.setFocus();
And Apply following code inside html-template/index.template.html. before HTML end tag.
<script type="text/javascript">
function onFlexInitialized()
{
//alert("onFlexInitialized");
<!-- Force the browser to set flex app with focus -->
document.getElementById("${application}").focus();
}
</script>

Answer 2

I solved it by adding this inside the body tag in html-template/index.template.html.
onLoad="window.document.Login.focus();"
and it worked corrctly. Thanks everyone :)

Answer 3

Index-template:
<div id="flashContent">
<script type="text/javascript">
function setFocus(){
window.document.getElementById("APPNAME").focus();
$('#txtUsername').focus();
$('#txtUsername').focusEnables=true;
}
</script>
</div>
Application:
private function init():void{
if (ExternalInterface.available) {
ExternalInterface.call('setFocus');
}
}