using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string pattern = @"requestId:";

        var input = @"kedar:123,requestId:333,prachi:123";

        Console.WriteLine("Hello World" + pattern);

         input=   Regex.Replace(input, pattern, string.Empty);

            Console.WriteLine("Returned string: " + input);

        string myString = "Do not put /*all*/ your eggs in /*one*/ basket";

       //     Console.WriteLine("Before regex: {0}", myString);

​

            myString = Regex.Replace(myString, @"/\*.*?\*/", string.Empty);            

            //Console.WriteLine("After regex: {0}", myString);

​

           // Console.WriteLine("Press any key to exit");

            Console.ReadLine();

    }

}