onkeypress="return isNumberKey(event, this);" call the function twice in IE8 per pressed in javascript
<p>Does anyone know what is going on here? When I pressed the key once, in IE8 it's always calls the function in javascript twice. It's working fine by only call the fundtion once when the keypredd in firefox but not in IE8.</p>

<p>HTML:</p>

<pre><code>&lt;input onkeypress="return isNumberKey(event, this);"  /&gt;
</code></pre>

<p>Javascript:</p>

<pre><code>function isNumberKey(evt, obj)
{

    alert('unavailable'). 
    return false

}
</code></pre>
