Javascript Function for data retrieved from mySQL Database with PHP

We have a drop down menu that calls in product prices from a mySQL database through a PHP loop. Through a Javascript function, the prices are added up with the onChange event handler. This works fine in Netscape, Safari etc., but not at all in Internet Explorer. In Explorer, the Javascript doesn't recognise the "value" selected in the drop down menu, even though the page as it appears in the end-user's browser clearly shows the values retrieved from the database between the <option> tags of the <select> menu.

Is anyone familiar with this problem or more importantly with a solution?

Thank you very much,
Moritz Gaede
Anne Schlotz