adding parameter to SourceURL link

I am having some trouble structuring my ReportFrame.SourceURL. My code as follows in my Controller page.

This is within my [HttpGet]

if (value != "")
        {
            string viewValue = value.Substring(0, value.IndexOf("|"));
            string viewType = value.Substring(value.IndexOf("|") + 1);
            UserType userType = summaryViewModel.SelectedUserTyp开发者_Go百科e;

            sSummaryViewModel.ReportFrame.SourceURL =
                WebPathHelper.MapUrlFromRoot(
                    string.Format("Reporting/Summary.aspx?beginDate={0}&endDate={1}&Id={2}&viewType=" + viewType,summaryViewModel.BeginDate, summaryViewModel.EndDate, viewValue));
        }

I want to add UserType after viewType so that my search will consider what has been selected from the UserType dropdown box.

Help will be great. :) Thanks

crikey....

if (value != "")
    {
        string viewValue = value.Substring(0, value.IndexOf("|"));
        string viewType = value.Substring(value.IndexOf("|") + 1);
        UserType userType = summaryViewModel.SelectedUserType;

        sSummaryViewModel.ReportFrame.SourceURL =
            WebPathHelper.MapUrlFromRoot(
                string.Format("Reporting/Summary.aspx?beginDate={0}&endDate={1}&Id={2}&viewType={3}&userType={4}",summaryViewModel.BeginDate, summaryViewModel.EndDate, viewValue,  viewType, userType));
    }