How to capture persons clothes sizes by country versions?

 Hi,
I need to obtain a persons measurements for wearing clothes, shoes etc such as below.
Neck / Shirt Collar size Trouser length Jacket Shoe size The problem is each size is different for UK, Europe and US versions
So far on a form I have a dropdown list for each measurement item  whichs show the selections like
ShoeSize DropDownList
38 eu / 5 uk / 6 us
40 eu / 6uk / 8 us
etc
 
I then show all the results from each DDL in a gridview which has a column for each item.
Instead of displaying all 3, which takes up space in the gridview, I want to just display one measurement
they have selected such as  "40" for shoe size 
So do this I guess I want to  allow the user to select which country is approaprite before they start the form and then t ...