Retrieve specific values from a query string.

var str = @"http://beta.firago.com/contact_us.aspx?item_name_1=Aito&item_quantity_1=11&item_price_1=875&item_options_1=pageLink%3A+aito.html%2C+bedrooms%3A+2+x+1+Bedroom&item_name_2=Peto&item_quantity_2=1&item_price_2=875&item_options_2=pageLink%3A+aito.html%2C+bedrooms%3A+2+x+1+Bedroom&return=success.html&cancel_return=cancel.html#.T-EgUMV5dXY";
var re = new Regex(@"item_name_\d[^&]*=([^&]*)&");
var matches = re.Matches(str);
foreach (var m in matches)
    Console.WriteLine(m);

var match = re.Match(str);
int matchCount = 0;
while (match.Success)
{
    Console.WriteLine("Match" + (++matchCount));
    for (int i = 1; i <= 2; i++)
    {
        Group g = match.Groups[i];
        Console.WriteLine("Group" + i + "='" + g + "'");
        CaptureCollection cc = g.Captures;
        for (int j = 0; j < cc.Count; j++)
        {
            Capture c = cc[j];
            System.Console.WriteLine("Capture" + j + "='" + c + "', Position=" + c.Index);
        }
    }
    match = match.NextMatch();
}
Console.ReadLine();