JavaScript - Test for an integer
<p>I have a text field that allows a user to enter their age. I am trying to do some client-side validation on this field with JavaScript. I have server-side validation already in place. However, I cannot seem to verify that the user enters an actual integer. I am currently trying the following code:</p>

<pre><code>    function IsValidAge(value) {
        if (value.length == 0) {
            return false;
        }

        var intValue = parseInt(value);
        if (intValue == Number.NaN) {
            return false;
        }

        if (intValue &lt;= 0)
        {
            return false;
        }
        return true;
    }
</code></pre>

<p>The odd thing is, I have entered individual characters into the textbox like "b" and this method returns true. How do I ensure that the user is only entering an integer?</p>

<p>Thank you</p>
