Code for reading querystring in hyperlink

[Milo]

Hi Guys,
need some help with a form I'm trying to make. Quite simply, I want to place a hyperlink on one page, that when clicked, takes the visitor to our form page. Quite simple. This is where it gets tricky (for me). I want the first form field "design" to be pre-filled with information retrieved from a querystring in the hyperlink.
ie. click here to go to form
When clicked, the form opens up and the field (name=design) is pre-filled with "Summer design".
I'm trying to make this orderform global so all that needs to change everytime is the design field. I've seen some examples, but they are quite complicated and I'm not sure where to put the code. Out of all the examples I've seen, Javascript looked the most simple as I'm not familiar with the most common result (ASP). I have good html knowledge, so was hoping to use html.