variables passed through URL

If I have have set a url to be displayed like this:

www.mysite.com/some_page.php?value=this
and wanted to tag on another value what would I seperate the
dtwo with/

Also since it is now displayed in the url and I need the value
in some area on my form.

How would I populate the value in a form tag?

<input type="text" value="<?echo (what goes here);?>"
name="something">

Thanks,


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