Creating a form and depending on selections output a link

So, I'm trying to setup a web page where the user can select a website and a format they want to display on said website.

I've done the form, but I also need to output a link when a user selects Google.com as the website and then selects 1000x1000 as the format I want the output to be "Google.com/?demo=1000x1000.

I think the best solution would be if I could store all these formats in a way and when you select "Google.com" as the website and then selects the format I want the link to be this for example: "website.com/?demo=format"

Is this possible at all? :)