Exception of type 'System.Web.HttpUnhandledException' was thrown.

System.Web.HttpUnhandledException (0x80004005): Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.ArgumentNullException: Value cannot be null.
    Parameter name: String
     at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
     at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
     at System.Int32.Parse(String s)
     at SitefinityWebApp.Widgets.Forms.ShelterRegisterSuccess.Page_Load(Object sender, EventArgs e) in C:\Workspaces\MCCV12_X2\Widgets\Forms\ShelterRegisterSuccess.ascx.cs:line 38
     at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)
     at System.Web.UI.Control.OnLoad(EventArgs e)
     at System.Web.UI.Control.LoadRecursive()
     at System.Web.UI.Control.LoadRecursive()
     at System.Web.UI.Control.LoadRecursive()
     at System.Web.UI.Control.LoadRecursive()
     at System.Web.UI.Control.LoadRecursive()
     at System.Web.UI.Control.LoadRecursive()
     at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
     at System.Web.UI.Page.HandleError(Exception e)
     at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
     at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
     at System.Web.UI.Page.ProcessRequest()
     at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)
     at System.Web.UI.Page.ProcessRequest(HttpContext context)
     at ASP.sfpageservice_ad98e801_1457_64c6_b6df_ff000043a4e7_mcc_main_aspx.ProcessRequest(HttpContext context)
     at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
     at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)
     at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)