I am tinkering with some JS to that will auto post a variable from an URL to a form, the aim being to auto apply a voucher on link click.
I’ve hosted it on github.com/Iheff/jQueryLink2FormSumbit. (there is a test page.)
I think I need to speak with the ASP guys it appears that the __doPostBack() function is working hand in hand with the ASP code. once I get some clues on how this works I can finish her up.