Remove key from querystring asp.net

protected void Page_Load(object sender, EventArgs e)
{
    string currentUrl = "http://localhost:39211/?page=2&sort=1&link=12&category=papers";


    string result = RemoveQueryString(currentUrl, "link");
    Response.Write(result);
}


public string RemoveQueryString(string url, string key)
{
    string pattern = key + "=[^&]+&?";
    System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex(pattern);
    return regex.Replace(url, "");
}

defaulttest

   
   
      add name="constr" connectionString="Data Source=JAGDISH;Initial Catalog=jaincmsdb;Integrated Security=false;" providerName="System.Data.SqlClient" 
     add name="constr" connectionString="Initial Catalog=tourdb;Data Source=JAGDISH;Integrated Security=SSPI;"
  add name="constr" connectionString="Data Source=XP8\SQL2008;Initial Catalog=jaincmsdb;User ID=sa;Password=sasql;" providerName="System.Data.SqlClient" 
     add name="constr" connectionString="Data Source=174.122.105.131;Initial Catalog=jaincmsdb;User ID=pathik;Password=pathik123;" providerName="System.Data.SqlClient"  

   
 

testing

Imports Microsoft.VisualBasic
Imports System.Data
Imports System.Data.SqlClient
Imports DAL

Namespace DAL

    Public Class db

        '''

        ''' Function return connection string with open state
        '''

        '''
        '''
        Public Function OpenConnection() As SqlConnection

            SqlConnection.ClearAllPools()
            Dim str As String = ""
            str = ConfigurationManager.ConnectionStrings("con").ConnectionString
            Dim cn As New SqlConnection
            cn.ConnectionString = str
            cn.Open()
            Return cn


        End Function

        '''

        ''' Function use the execute non query
        '''

        '''
        '''
        '''
        Public Sub ExecuteNonQuery(ByVal strQuery As String, Optional ByVal strFunctionName As String = "")

            HttpContext.Current.Trace.Warn(strFunctionName & ":" & strQuery)
            Dim cn As New SqlConnection
            Dim cmd As New SqlCommand


            Try

                cn = OpenConnection()
                cmd.Connection = cn
                cmd.CommandType = CommandType.Text
                cmd.CommandText = strQuery
                cmd.ExecuteNonQuery()

            Finally

                cn.Close()

            End Try

        End Sub


        '''

        ''' Function return dataset
        '''

        '''
        '''
        '''
        Public Function FillDataset(ByVal strQuery As String, Optional ByVal strFunctionName As String = "") As DataSet

            HttpContext.Current.Trace.Warn(strFunctionName & ":" & strQuery)
            Dim cn As New SqlConnection
            Dim cmd As New SqlCommand
            Dim dst As New DataSet
            Dim da As New SqlDataAdapter

            Try

                cn = OpenConnection()
                cmd.Connection = cn
                cmd.CommandType = CommandType.Text
                cmd.CommandText = strQuery
                cmd.ExecuteNonQuery()
                da = New SqlDataAdapter(cmd)
                da.Fill(dst)

            Finally

                cn.Close()

            End Try

            Return dst

        End Function

        '''

        ''' Function return dataset
        '''

        '''
        '''
        '''
        Public Function FillDatareader(ByVal strQuery As String, Optional ByVal strFunctionName As String = "") As SqlDataReader

            HttpContext.Current.Trace.Warn(strFunctionName & ":" & strQuery)
            Dim cn As New SqlConnection
            Dim cmd As New SqlCommand
            Dim dr As SqlDataReader

            cn = OpenConnection()
            cmd.Connection = cn
            cmd.CommandType = CommandType.Text
            cmd.CommandText = strQuery
            dr = cmd.ExecuteReader()
            Return dr


        End Function


    End Class

End Namespace