How to change a background color in Javascript based on an entered value
<p>I am trying to create a page that, upon entering a temperature of or higher than 70, the result page will turn red, and if the temperature is below 70, then it will turn blue. I already have a sample page for the first part of the code for the submit page. I just don't want the words to turn colors, I want the entire page to turn colors based on the temperature. Can anyone help?</p>

<pre><code>&lt;html&gt;
&lt;body&gt;
&lt;?php
if (isset($_POST['temperature'])): //isset determines if var has valid contents, even empty string

    //if var is set, show what it contains
    $myFahrenheit = (int)$_POST['temperature']; //cast value sent via post to an integer

    $myCelsius = intval(($myFahrenheit-32) * (5/9)); //calc celsius
    echo '&lt;h1&gt;&lt;font color="blue"&gt;You entered ' . $myFahrenheit . ' in Fahrenheit!!&lt;/font&gt;&lt;br /&gt;';
    echo '&lt;h1&gt;&lt;font color="red"&gt; It is '. $myCelsius .' in celsius!!&lt;/font&gt;&lt;br /&gt;';
    //put link on page to reset form
    print '&lt;a href="' . $_SERVER['PHP_SELF'] . '"&gt;Reset page&lt;/a&gt;';
else:
    //show form
?&gt;
    &lt;!--Note the server variable indicating the page we are on --&gt;
    &lt;form action="&lt;? print $_SERVER['PHP_SELF']; ?&gt;" method="post"&gt;
    Enter your temperature in Fahrenheit &lt;input type="text" name="temperature"&gt;&lt;br&gt;
    &lt;input type="submit" value="Show me the temperature in celsius!!"&gt;
    &lt;/form&gt;
&lt;?
endif;
?&gt;
&lt;/body&gt;
&lt;/html&gt;
</code></pre>
