java Script Error:Undefined

See more:

VB

ASP.NET

Hai i am using DropDownList and i am validating the DropDownlist at the time it's throw one Error for:Undefined this is my Error Please Help me where i done mistake below is my code and Java script :

UI:

<asp:DropDownList ID="ddrlclientststus" runat="server" CssClass="txtboxadddetails">
                                <asp:ListItem>--Select--</asp:ListItem>
                                <asp:ListItem>Open</asp:ListItem>
                                <asp:ListItem>Closed</asp:ListItem>
                            </asp:DropDownList>

<script type="text/javascript">
        function validate() {
            debugger;
            var summary = "";
            summary += isvalidClient();
            summary += isvaliedUserName();
            summary += isvaliedStatus();
if (summary != "") {
                alert(summary);
                return false;
            }
            else {
                return true;
            }
        }
function isvalidClient() {
            var CliID
            var temp = document.getElementById("<%=txtClientId.ClientID%>");
            CliID = temp.value;
            if (CliID == "") {
                return ("Please Enter Client ID" + "\n");
            }

            else {
                return "";
            }
        }

        function isvaliedUserName() {
            var CliID
            var temp = document.getElementById("<%=txtClientName.ClientID%>");
            CliID = temp.value;
            if (CliID == "") {
                return ("Please Enter Client Name" + "\n");
            }

            else {
                return "";
            }
        }
//it's error Showing hear only this funcation(isvaliedStatus)
 function isvaliedStatus() {
            if (document.getElementById('<%=ddrlclientststus.ClientID %>').selectedIndex == 0) {
                return ("Please Select Ststus" + "\n");
            }
        }