Upload file button works in all browsers except IE

Hey fellow freelancers! I just noticed an issue with my client's website. It's a Magento installation for a sign shop. Each product page provides the visitor with options to select from, such as "banner size, finishing options, etc.", and also the ability to upload a file. Firefox and Chrome work perfectly, but Internet Explorer has a small problem (go figure). The form's "choose file" button "should" initiate the "open file" dialog box. But instead, it just adds the product to the cart, bypassing everything. Hmmm... Send me a PMB and I'll send you a link to the website. IMPORTANT: Experienced developers with high feedback rating and completion only (4.7 minimum requirement AND must have > 20 feedback). Personal messages are appreciated. All other messages will be ignored, so please don't waste your time bidding if you don't meet the above criteria. Also, if you place a bid without also sending me a PMB asking for the demo link, I will also ignore/hide your bid. In other words... serious inquiries only. :) Let me know if you have any questions. Thanks!