how to do multiplication on input fields
<p>I have the following code and I want to be able to perform multiplication when a value is typed into the "quantity" input using <code>.keyup()</code>. So basically a user inputs a number into the "quantity" input and it will multiply its value by the hidden input "cash5" and "amazon5" and display the results of the multiplication in the labels "amazon5totalpoints" and "amazon5totalcash". Also how would you make the "quantity" input only accept integers? Thanks you.</p>

<pre><code>&lt;input name="quantity" type="text" id="quantity" /&gt;

&lt;input name="amazon5" type="hidden" id="amazon5" value="450"&gt;
&lt;input name="cash5" type="hidden" id="cash5" value="5"&gt;
&lt;label id="amazon5totalpoints"&gt;&lt;/label&gt;
&lt;label id="amazon5totalcash"&gt;&lt;/label&gt;

&lt;input name="amazon25" type="hidden" id="amazon25" value="3150"&gt;
&lt;input name="cash25" type="hidden" id="cash25" value="25"&gt;
&lt;label id="amazon25totalpoints"&gt;&lt;/label&gt;
&lt;label id="amazon25totalcash"&gt;&lt;/label&gt;

&lt;input name="amazon50" type="hidden" id="amazon50" value="5900"&gt;
&lt;input name="cash50" type="hidden" id="cash50" value="50"&gt;
&lt;label id="amazon50totalpoints"&gt;&lt;/label&gt;
&lt;label id="amazon50totalcash"&gt;&lt;/label&gt;
</code></pre>
