how to using jquery to validate it?
<p>there is an input type box as this:</p>

<pre><code>   &lt;input type="text" name="xlnum" id="xlnum" /&gt;
&lt;input type="submit" value="Submit" id="submit" /&gt;
</code></pre>

<p>the allowed value that are inputted in the text box is number. but it style must be as this:</p>

<pre><code>number1,number1,number1,number1,number1.... eg(1,2,,12,35,654,....)
</code></pre>

<p>if the user types the wrong style. i want to give him  a tip use jquery.how do i do. i don't know how to write the <code>if</code> part.
eg:</p>

<pre><code>$('#submit').click(function() {
 if($('#xlnum').val()=='' &amp;&amp; ...)...
})
</code></pre>
