Problem to call this web Method get_node_server_list()

  using System;   
   using System.Collections;   
   using System.Configuration;   
   using System.Data;   
   using System.Linq;   
   using System.Web;   
   using System.Web.Security;   
   using System.Web.UI;   
   using System.Web.UI.HtmlControls;   
   using System.Web.UI.WebControls;   
   using System.Web.UI.WebControls.WebParts;   
   using System.Xml.Linq;   
   using System.Web.Services.Description;   
   using System.Net;   
   using System.Security.Cryptography.X509Certificates;     
   using System.Security;   
   namespace ConsumeDummy   
   {   
   public class TrustAllCertificatePolicy : System.Net.ICertificatePolicy   
   {   
   public TrustAllCertificatePolicy()   
   { }   
   public bool CheckValidationResult(ServicePoint sp,X509Certificate cert, WebRequest req, int problem)   
   {   
   return true;   
   }   
   }   
   public partial class _Default : System.Web.UI.Page   
   {   
   protected void Page_Load(object sender, EventArgs e)   
   {   
   System.Net.ServicePointManager.CertificatePolicy = new TrustAllCertificatePolicy();   
   //System.Net.ServicePointManager.CertificatePolicy = new TrustAllCertificatePolicy();   
   System.Net.NetworkCredential objCredential = new System.Net.NetworkCredential("readonly", "readonly");   
   Node.ITCMLocalLBNode myNode = new Node.ITCMLocalLBNode();               
   System.Net.NetworkCredential myCred = new System.Net.NetworkCredential();   
   myNode.Url = "https://143.166.217.6:" + 443 + "/iControl/iControlPortal.cgi";   
   //Debug.WriteLine(myNode.Url);   
   // Turn on pre Auth?    
   myNode.PreAuthenticate = true;   
   // Credentials to connect (In Production we should use read only)    
   myCred.UserName = "readonly";   
   myCred.Password = "readonly";   
   // Pass credentials to the BigIP    
   myNode.Credentials = myCred;   
   // Empty the NodeList    
   NodeList.Items.Clear();   
   // Get List of Nodes    
   Node.ITCMCommonIPPortDefinition[] myNodeDefs = null;   
   myNodeDefs = myNode.get_node_server_list();   
   int[] myNodeStat = null;   
   myNodeStat = myNode.get_state_ex(myNodeDefs);   
   int i = 0;   
   for (i = 0; i <= myNodeDefs.Length; i++)   
   {   
   NodeList.Items.Add(myNodeDefs[ i ].address + ":" + myNodeDefs[ i ].port );   
   Console.WriteLine(myNodeDefs[ i ].address);   
   }    
   /*long l1, l2;   
   int s1;   
   l1 = (long)(IPAddressToNumber("10.166.218.79"));   
   l2 = 80;               
   node_Def.address = l1;   
   node_Def.port = l2;   
   long[] arrStr = new long[1000];   
   s1 = a1.get_availability(node_Def) ;   
   node_Def1=a1.get_node_server_list();      
   //s1=a1.get_state(node_Def);   
   //arrStr=a1.get_list();       
   //s1=a1.get_dynamic_ratio(l1);    
   Label1.Text = s1.ToString() ;   
   //Label1.Text = arrStr[0].ToString() ;   
   //node_Def1 = a1.get_node_server_list();     
   /*   
   Node.ITCMLocalLBNode myNode = new Node.ITCMLocalLBNode();    
   System.Net.NetworkCredential myCred = new System.Net.NetworkCredential();    
   if (string.IsNullOrEmpty(Hostname.Text)) {    
   Interaction.MsgBox("No Hostname Listed", MsgBoxStyle.Critical, "Error");    
   return;    
   }    
   // URL to BigIP    
   myNode.Url = "https://" + Hostname.Text + ":" + 443 + "/iControl/iControlPortal.cgi";    
   Debug.WriteLine(myNode.Url);    
   // Turn on pre Auth?    
   myNode.PreAuthenticate = true;    
   // Credentials to connect (In Production we should use read only)    
   myCred.UserName = Username.Text;    
   myCred.Password = Password.Text;    
   // Pass credentials to the BigIP    
   myNode.Credentials = myCred;    
   // Empty the NodeList    
   NodeList.Items.Clear();    
   // Get List of Nodes    
   Node.ITCMCommonIPPortDefinition[] myNodeDefs = null;    
   myNodeDefs = myNode.get_node_server_list;    
   int[] myNodeStat = null;    
   myNodeStat = myNode.get_state_ex(myNodeDefs);    
   int i = 0;    
   for (i = 0; i <= myNodeDefs.Length; i++) {    
   NodeList.Items.Add(myNodeDefs(i).address + ":" + myNodeDefs(i).port, Convert.ToBoolean(myNodeStat(i)));    
   Console.WriteLine(myNodeDefs(i).address);    
   }    
   */   
   }   
   public double IPAddressToNumber(string IPaddress)   
   {   
   int i;   
   string [] arrDec;   
   double num = 0;   
   if (IPaddress == "")   
   {   
   return 0;   
   }   
   else   
   {   
   arrDec = IPaddress.Split('.');   
   for(i = arrDec.Length - 1; i >= 0 ; --i)   
   {   
   num += ((int.Parse(arrDec[ i ])%256) * Math.Pow(256 ,(3 - i )));   
   }   
   return num;   
   }   
   }   
   }   
   }   
   /*Imports System.Net.SecurityImports    
   * System.Security.Cryptography.X509Certificates2.before calling webservice:ServicePointManager.ServerCertificateValidationCallback = New RemoteCertificateValidationCallback(AddressOf customXertificateValidation)3.Custom certificate runnerrivate Shared Function customXertificateValidation(ByVal sender As Object, ByVal cert As X509Certificate, ByVal chain As X509Chain, ByVal Errora As SslPolicyErrors) As Boolean        Return TrueEnd Function*/