The 2nd Drop Down List is populated based on the values

Question

I have a .aspx page that has 2 drop down lists on it.

The 2nd Drop Down List is populated based on the values from the first drop down list.

 When I select Values from the second Drop Down List, and search, it gives records. when I select values for second drop down list and select the date picker from and through it does not giving any records. Because the 2nd drop down list box is holding some value back there and it is not resetting to 0. what do I need to do to reset value to 0 of the 2nd drop down list box.

below is page load event code.

protected void Page_Load(object sender, EventArgs e)

{

this.Master.ShowSideNavagation = false;

 ucGetIndividual.HospitalID = (Int16)this.UserAccess.HospitalID;

ucLocation.HospitalID = this.UserAccess.HospitalID;

ucAttendance.HospitalID = this.UserAccess.HospitalID;

if (!Page.IsPostBack)

        {

 LoadDropDowns();      

this.vsSummary.HeaderText = ErrorHelper.GetErrorMessage("ValidationSummaryHeaderText");

this.cvActionType.ErrorMessage = ErrorHelper.GetErrorMessage("IsRequired").Replace"{FieldName}", "Action date");

         

//Concatenate the Client ID of Report title Textbox, Group By drop down and Sort by Drop down

 btnGenerateReport.Attributes.Add("onClick", string.Format("ShowDialog('{0}/PopUpReportViewer.aspx?report=10',  '{1}', '{2}', '{3}', '{4}');return false;",

                                       

this.ReportPath, tbTitle.ClientID, ddlGroupBy.ClientID, ddlSortBy.Client, cbInclude.ClientID));

      

this.SpellandMaxLimitCheck(this.tbTitle, 100, "Title"); //Spell check

rdpFromDate.SelectedDate = DateTime.Now;

rdpToDate.SelectedDate = DateTime.Now;

rfvFromDate.ErrorMessage = ErrorHelper.GetErrorMessage("IsRequired").Replace("{FieldName}", "From date");

rfvToDate.ErrorMessage = ErrorHelper.GetErrorMessage("IsRequired").Replace("{FieldName}", "Through  date");

cvFromDateToDate.ErrorMessage =

String.Format(ErrorHelper.GetErrorMessage("CompareValidatorErrorMessage"), "From date", "through  date");

ddlActionType.SelectedValue = ScheduledStatusTypeID.ToString();           

this.gvSearchResults.Attributes.Add("summary", GvSearchCompleteSummary);

this.ucGetIndividual.TXT_CssClass = "textbox";

this.ucGetIndividual.BTN_CssClass = "formInputButton";

this.ucGetIndividual.DDL_CssClass = "dropDown";  

this.btnSearch.Attributes.Add("onclick", CommonFunctions.ChangeValidationSummaryDisplayMode(

vsSummary.ClientID, ValidationSummaryDisplayMode.BulletList.ToString()));

this.btnReports.Attributes.Add("onclick", CommonFunctions.ChangeValidationSummaryDisplayMode(vsSummary.ClientID,

ValidationSummaryDisplayMode.BulletList.ToString()));

     }

    }

#endregion