Extract Search Keyword from Google, Yahoo and other search URL in C#

using System;
using System.Collections.Generic;
using System.Net;
using System.Text;
using System.Web;
using System.Text.RegularExpressions;
 
 
namespace forgetcode
{
    
    class Program
    {
         static void Main(string[] args)
        {
           
             Uri referrer = HttpContext.Current.Request.UrlReferrer;
            if (referrer != null)
            {
                string original = referrer.OriginalString.ToLower();
                string keyword = GetKeyword(original);
                Console.WriteLine("Visitor Searched For "+keyword);
            }
        }
        private static string GetKeyword(string strU)
        {
            Regex regKeyword = new Regex("(p|q)=(?<keyword>.*?)&", RegexOptions.IgnoreCase | RegexOptions.Multiline);
            Regex regSnippet = new Regex("forgetcode.com.*%2F(?<id>\\d+)%2F", RegexOptions.IgnoreCase | RegexOptions.Multiline);
            Match match = regKeyword.Match(strU);
            string keyword = match.Groups["keyword"].ToString();
            // Get the decoded URL
            string result = HttpUtility.UrlDecode(keyword);
            // Get the HTML representation
            result = HttpUtility.HtmlEncode(result);
            
            return result;
 
        }
     }
}