isNullorWhitespace in javascript
<p>Is there a Javascript equivalent to isNullOrWhitespace so I can check if a textbox on the client side has any text in it, not just spaces or empty/null?</p>

<p>I'd rather do this on the client side first than post back the contents and validate server side, even though I will do that as well.</p>

<p>Thanks!</p>
