Add the following code to the document you want to use the script in (before any calls to the getQuicktimeVersion() function):
<script type="text/javascript" src="quicktime_detect.js">
//<![CDATA[
function getQuicktimeVersion() { return null; };
//]]>
</script>
If the quicktime_detect.js file is in a different directory than the html document, be sure to include the relative path to the Javascript file in the src attribute value.
The getQuicktimeVersion() function returns:
The version number, if Quicktime is installed.
The value 0, if Quicktime isn't installed.
The value quicktimeVersion_DONTKNOW (see the example on how to use this value), if it is not possible to check for Quicktime (like on IE4.5 Mac, for instance).
Have a nice day.
This script is released under a Creative Commons License.