ASP.NET

 Protected Sub ValidateDuration(ByVal sender As Object, ByVal args As ServerValidateEventArgs)
    Dim validator As Control = DirectCast(sender, Control)
    Dim row As Control = validator.NamingContainer
   Dim startHour As Integer = Integer.Parse(DirectCast(row.FindControl("startHour"), DropDownList).SelectedValue)
    Dim startMinutes As Integer = Integer.Parse(DirectCast(row.FindControl("startMinutes"), DropDownList).SelectedValue)
    Dim startAmPm As String = DirectCast(row.FindControl("startAmPm"), DropDownList).SelectedValue

    Select Case startAmPm
        Case "AM"
            If True Then
                If startHour = 12 Then
                    startHour = 0
                End If
                Exit Select
            End If
        Case "PM"
            If True Then
                If startHour <> 12 Then
                    startHour += 12
                End If
                Exit Select
            End If
        Case Else
            If True Then
                args.IsValid = True
                Return
            End If
    End Select

    Dim endHour As Integer = Integer.Parse(DirectCast(row.FindControl("endHour"), DropDownList).SelectedValue)
    Dim endMinutes As Integer = Integer.Parse(DirectCast(row.FindControl("endMinutes"), DropDownList).SelectedValue)
    Dim endAmPm As String = DirectCast(row.FindControl("endAmPm"), DropDownList).SelectedValue

    Select Case endAmPm
        Case "AM"
            If True Then
                If endHour = 12 Then
                    endHour = 0
                End If
                Exit Select
            End If
        Case "PM"
            If True Then
                If endHour <> 12 Then
                    endHour += 12
                End If
                Exit Select
            End If
        Case Else
            If True Then
                args.IsValid = True
                Return
            End If
    End Select

    hourDiff = endHour - startHour
    If endMinutes < startMinutes Then
        hourDiff -= 1
    End If
    'Response.Write(hourDiff)
    'Response.End()
    args.IsValid = hourDiff >= 4
End Sub

<asp:HyperLink ID="hdReserve" class="js_siteid"  runat="server" Text="Select"
    NavigateUrl='<%# String.Format("ReserveFacility.aspx?id={0}&facilityFees={1}&depoitAmt={2}&cancelAmt={3}&keydeptAmt={4}&extrahour={5}", Eval("siteId"), Eval("RentalFeeAmount"), Eval("DepositAmount"), Eval("CancellationAmount"), Eval("DepositAmount"), Eval("ExtraHourAmount")) %>'
/>

$(function(){

    var parseTime = function(container, prefix){
        var hour = parseInt(container.find("select[name$=" + prefix + "Hour]").val(), 10);
        var minutes = parseInt(container.find("select[name$=" + prefix + "Minutes]").val(), 10);
        var amPm = container.find("select[name$=" + prefix + "AmPm]").val();

        switch (amPm) {
            case "AM": {
                if (hour === 12) { hour = 0; }
                break;
            }
            case "PM": {
                if (hour !== 12) { hour += 12; }
                break;
            }
            default: {
                return null;
            }
        }

        return { hour: hour, minutes: minutes };
    };

    // TODO: Check that this selector returns the correct elements:
    $("a.js_siteid").each(function(){

        var me = $(this);
        var row = me.closest("tr");
        var baseUrl = me.attr("href");

        row.on("change", "select[name$=ddlPartySize], select[name$=Hour], select[name$=Minutes], select[name$=AmPm]", function(){

            var url = baseUrl;
            var groupSize = row.find("select[name$=ddlPartySize]").val();
            if (groupSize) { url += "&groupsize=" + encodeURIComponent(groupSize); }

            var startTime = parseTime(row, "start");
            var endTime = parseTime(row, "end");
            if (startTime && endTime){
                var hourDiff = endTime.hour - startTime.hour;
                if (endTime.minutes < startTime.minutes) { hourDiff--; }
                url += "&hoursdiff=" + hourDiff.toString();
            }

            me.attr("href", url);
        });
    });
});

<script type="text/javascript">
              $(window).load(function () {
                  $("#txtFromDate").datepicker();
                  $('#timeStart').timepicker({ showPeriod: true,
                      onHourShow: OnHourShowCallback,
                      onMinuteShow: OnMinuteShowCallback
                  });

                  $("#txtToDate").datepicker();
                  $('#timeEnd').timepicker({ showPeriod: true,
                      onHourShow: OnHourShowCallback,
                      onMinuteShow: OnMinuteShowCallback
                  });
                  function OnHourShowCallback(hour) {
                      if ((hour > 20) || (hour < 6)) {
                          return false; // not valid
                      }
                      return true; // valid
                  }
                  function OnMinuteShowCallback(hour, minute) {
                      if ((hour == 20) && (minute >= 30)) { return false; } // not valid
                      if ((hour == 6) && (minute < 30)) { return false; }   // not valid
                      return true;  // valid
                  }
                  $('#btnSearch').on('click', function () {
                      var sDate = $("#txtFromDate").val();
                      var sTime = $("#timeStart").val();

                      var eDate = $("#txtToDate").val();
                      var eTime = $("#timeEnd").val();

                      var startDate = new Date(sDate + " " + sTime).getHours();
                      var endDate = new Date(eDate + " " + eTime).getHours();

                      //Calulate the time difference
                      var hourDiff = endDate - startDate;
                      //alert(hourDiff);

                      //Check if hour difference is less than 4 hours and show the message accordingly
                      if (hourDiff < 4) {
                          var r = false; $($("<div>A mininum of 4 hours is required!</div>")).dialog({ closeOnEscape: false, resizable: false, modal: true, open: function (event, ui) { $(".ui-dialog-titlebar-close").hide(); }, buttons: { Close: function () { r = false; $(this).dialog("close"); } }, close: function () { return r; } });
                          return false;
                      }

                      //Add the check condition if the user is above the 4 hours time frame
                      if (hourDiff > 4) {
                          var r = confirm("There may be additional fees for going over the 4 hours!");
                          if (r == true) { // pressed OK
                              return true;
                          } else { // pressed Cancel
                              return false;
                          }
                      }
                  });
              });
</script>

<asp:CustomValidator ID="CustomValidator1" runat="server"
ControlToValidate="endHour"
ErrorMessage="A minimum of four hours is required."
Text="*"
SetFocusOnError="True"
OnServerValidate="ValidateDuration"
ClientValidationFunction="ValidateDuration" />

samflex wrote:

If I can resolve the issue of ValidateDuration is undefined error that happens when I use it below:

samflex wrote:

So when a user clicks the link, to be redirected to ReserveFacility.aspx, the total overage hours and associated fees must be passed to that page as well.

void Button_Click(object sender, EventArgs e) {
   // The following code to delete it
   string file = "You can pass the location from a parameter.";
   File.Delete(file);
}