title: How does link with href parameter like "ymsgr:sendim?username" works, what kind of header does it send
body: <p>I want to make php script that replace the execution of this kind of a link:</p>
  
  <pre><code>&lt;a href="ymsgr:sendim?tonystark"&gt;YM! Iron Man&lt;/a&gt;
  </code></pre>
  
  <p>So when the php script is called/executed, it will open Yahoo Messenger application window that prepared to send IM to tonystark.</p>
  
  <p>Can I use header instead? but what type of header it would be?</p>