Updating a bindable value in the Application Skin in Flex 4

Question

I've created a skin for my Flex 4 application. It has a header section, where I have a Label component with the text value being assigned to a Bindable string defined in the skin file itself.

<fx:Script>
    <![CDATA[
        [Bindable]
        public var loginName:String = "Test";
    ]]>
</fx:Script>

How can I change this string value available in the skin from the Application which uses it?

Please provide your valuable inputs.