updating numbers in dynamic crm 2011 using plugin

first:
need to take the early bond and add it on existing items
now we can add the references.

if you create a new record then the filed value need to take the amount of field value.


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Xrm;
using System.Diagnostics;
using System.ServiceModel;
using Microsoft.Xrm.Sdk;
using Microsoft.Xrm.Sdk.Query;
using System.Windows.Browser;
using System.Net;
using System.IO;
using System.ServiceModel.Description;
using Microsoft.Xrm.Sdk.Discovery;
using Microsoft.Xrm.Sdk.Messages;
using Microsoft.Crm.Sdk.Messages;
using Microsoft.Xrm.Sdk.Client;

namespace super.Plugin.TimeCaluculation
{
    public class TimecaluculationCreate : IPlugin
    {
        public int totaltime;

        public Entity entity1;

        public IOrganizationService service;
        public IPluginExecutionContext context;

        public void Execute(IServiceProvider serviceProvider)
        {


            IPluginExecutionContext context = (IPluginExecutionContext)
            serviceProvider.GetService(typeof(IPluginExecutionContext));

            Entity entity;

            // Check if the input parameters property bag contains a target
            // of the create operation and that target is of type Entity.
            if (context.InputParameters.Contains("Target") && context.InputParameters["Target"] is Entity)
            {

                // Obtain the target business entity from the input parameters.
                entity = (Entity)context.InputParameters["Target"];

                // Verify that the entity represents a contact.
                if (entity.LogicalName != "new_item")
                {
                    return;
                }
            }
            else
            {
                return;
            }

            try
            {
                IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
                IOrganizationService service = serviceFactory.CreateOrganizationService(context.UserId);

                Entity entity1 = (Entity)context.InputParameters["Target"];
                if (context.MessageName == "Create")
                {
                    int timeonitems = Convert.ToInt32(entity1["new_time"]);
                    EntityReference var1 = (EntityReference)entity1["new_lid"];


                    ColumnSet cols = new ColumnSet(
                                         new String[] { "new_maxtime", "new_name" });

                    var contact1 = service.Retrieve("new_la", var1.Id, cols);

                    if (contact1.Attributes.Keys.Contains("new_maxtime") == false)
                    {
                        totaltime = timeonitems;
                    }


                    else
                    {
                        int timeofitems = Convert.ToInt32(contact1["new_maxtime"]);

                        totaltime = timeofitems + timeonitems;
                    }

                    contact1["new_maxtime"] = totaltime;

                    service.Update(contact1);
                }
            }
            catch (FaultException<OrganizationServiceFault> ex)
            {
                throw new InvalidPluginExecutionException("An error occurred in the plug-in.", ex);
            }


        }

    }
}

it will update the new_maxtime filed with count.