Apparently it's difficult to get corn syrup in Europe. Here's an easy recipe to make you're own:
To make 1 cup [250 ml] of corn syrup, boil together 1¼ cups [265 grams] sugar and ⅓ cup water [85 ml] until all the sugar is dissolved. This is most easily achieved by measuring the water in a glass measuring cup (500 ml) then heating it in the microwave until boiling. Add the sugar and stir well . Cover with plastic wrap and cook for 2 minutes on high power. Stir well with a wooden spoon then cover and heat again for another 2 minutes. If not all the sugar is dissolved, repeat.