Object reference not set to an instance of an object.

Question

appproperty.cs

    public DataTable getclientresource(string para_ResourceType ,object MobileNo )
        {

            DataTable _getclientresource = maincon.getDataTable("select distinct ClientMaster.ClientName,ClientResources.DisplayName,LinkClientUser.Clientid,LinkClientUser.ClProductId,ClientResources.AccessKey  FROM LinkClientUser"
                       + " LinkClientUser inner join softplus_clients.ClientMaster ClientMaster on LinkClientUser.clientid = ClientMaster.clientid "
                       + " inner join ClientResources ClientResources on ClientResources.ClProductId = LinkClientUser.ClProductId  and ClientResources.ResourceType = LinkClientUser.ResourceType and ClientResources.AccessKey = LinkClientUser.AccessKey "
                       + " where LinkClientUser.mobileno=  '" + MobileNo + "' and LinkClientUser.ResourceType = '" + para_ResourceType + "' ", "dtcomplist");

                return _getclientresource;


        }

Controller


        object mobileno;
        appproperty app = new appproperty();
        Profile p;

        public ActionResult CompanyList()
        {

            mobileno = Session["MobileNo"];
            DataTable dt = new DataTable();
            dt = app.getclientresource("LBROKSYS", mobileno);
            foreach(DataRow dr in dt.Rows)
            {
                p.Displayname = dr["DisplayName"].ToString();
                p.ClProductId = dr["ClProductId"].ToString();
                Session["ClProductId"] = dr["ClProductId"].ToString();

            }
           return View();
        }