title: Javascript Async=true Attribute
body: <p>I see this code sample in a certain unnamed vendor's documentation.  It appears to load a script asynchronously, then invoke a function from it thereafter.  I realize that the if-undefined check will prevent an overt error, but is this not totally incorrect?</p>
  
  <p>I believe that in IE8/9 it will work properly but block execution until the LOADER_URL script loads and executes; and I believe in many other browsers that do support the async attrbute, this will simply result in the inline-block executing the code inside the if-block only part of the time.  The documentation states "tags are asynchronous and do not slow the loading of your pages."</p>
  
  <pre><code>&lt;script type="text/javascript" src="LOADER_URL" async="true"&gt;&lt;/script&gt;
  &lt;script type="text/javascript"&gt;
  if (typeof (OBJECT_DEFINED_IN_LOADER_URL) != "undefined") { OBJECT_DEFINED_IN_LOADER_URL.Load(false); }
  &lt;/script&gt;
  </code></pre>
  
  <p>Looking at an earlier version of their documentation, it did not have the suggestion of the async attribute and did not make this claim.  Did some technical writer make a mistake and say "yeah, that'll work" without testing adequately in all browsers?  In IE &lt;= 9 it will work all the time.  And since async code is uber-fun to debug ... maybe it worked for them ...</p>
  
  <p>That's my suspicion :)</p>