 <p>1) no, this should be a custom (not standard) <strong>popup()</strong> function.</p> <p>2) Your code uses someUrl to extract a value with <code>fmt:message</code> and then paste it into the popup.</p> <p>Following is an illustration on how <strong>fmt:message</strong> works:</p> <p>let's introduce the <code>&lt;fmt:message&gt;</code> action. If you really wanted to do the bare-bones amount of work necessary to build an internationalized application,is the only action that you'll need to consider. The action takes advantage of the LocalizationContext (which we talk about in the next section).By using the ,you can output values from your resource bundles as simply as:</p> <pre><code>&lt;fmt:message key="welcome"/&gt; </code></pre> <p>The appropriate resource bundle will be used to look up the key "welcome" and the translated string will be provided. This is about as easy as it gets to incorporate international support into your application. The action also supports parameterized content, also called parametric replacement. For example, you can provide variables that will be used within the string used by the key attribute. Say we want to personalize our welcome page and pass the name of a user so that we can welcome them. To do this, we use the <code>&lt;fmt:param&gt;</code> subtag. We will talk about this in more detail later in this chapter, but as a quick example, so that you are familiar with the format, the action might look like:</p> <pre><code>&lt;fmt:message key="welcome"&gt; &lt;fmt:param value="${userNameString}"/&gt; &lt;/fmt:message&gt; </code></pre> <p>taken from <a href="http://www.javaranch.com/journal/2003/09/AnIntroductionToJstl.html" rel="nofollow">here</a></p>