I need a function that I can apply to a string to return the string value or "00" if it is null
<p>Is there some function that I can apply to a string so that the string will return its value if the string is not equal to null or the value "00" if it is null. </p>

<pre><code>var abc = myVariable.xxxx;

gives abc = "AB" if myVariable == "AB";
gives abc = "00" if myVariable == null;
</code></pre>
