The Request.QueryString(name) method returns a VB Collection object. This link defines the properties and methods of the Collection object. The main ones we are concerned with are Count and Item.
The Count property (as mentioned in my previous article) gives a count of the number of items it the collection and the Item property allows you to get at the individual items. Two thing should be noted about the Item property: first that it is a method not an array and second that it is one based not zero based, so the first item is retrieved using Item(1) not Item[0].
For example, if your QueryString contains "widget=abc&widget=xyz" and you do:
var widget = Response.QueryString("widget");
widget.Count // 2
widget.Item(1) // "abc"
widget.Item(2) // "xyz"
