Ecommerce SiteTo Order Via FRAMES

Want my existing website ([login to view URL]) to use FRAMES to place on-line orders from an ecommerce vendor ([login to view URL]) in Internet Explorer. You can set up an account and order directly at the vendor site, but the same transaction does NOT work when you try it through a FRAME on my website (places a cookie with my ID # so when they order I get credit). I’m guessing it’s the SSL certificate, cookie, or script not being properly set up to work with the FRAME and hoping it's a simple fix. If it’s too involved to fix my site and you have another ecommerce template, I’m open to redesigning my website as long as you can order though the FRAME (don’t want a pop-up as future customers should refer people to MY site and not the vendor’s site directly). Also, I’m open to any suggestions or improvements you may recommend at a reasonable cost. Thank you!