Why the error occurs javascript runtime error: object doesn't support property or method 'dyndatetime'

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C#

ASP.NET

Ajax

jQuery

hello everyone,
Here i have jquery for calendar and autocomplete textbox(using ajax).
but i gives following runtime error

JavaScript runtime error: Object doesn't support property or method 'dynDateTime'

What I have tried:

Coding for Calendar is as follows,

<link href="Styles/calendar-blue.css" rel="stylesheet" type="text/css" />
 <script src="Scripts/jquery-1.4.1.min.js" type="text/javascript"></script>
<script src="Scripts/jquery.dynDateTime.min.js" type="text/javascript"></script>
<script src="Scripts/calendar-en.min.js" type="text/javascript"></script>

<script type="text/javascript">
     $(document).ready(function () {
         $("#<%=txtDOB.ClientID %>").dynDateTime({
             //        $("#TextBox2").dynDateTime({

             showsTime: false,
             ifFormat: "%Y-%m-%d",
             //            ifFormat: "%Y/%m/%d %H:%M",
             daFormat: "%l;%M %p, %e %m, %Y",
             align: "BR",
             electric: false,
             singleClick: false,
             displayArea: ".siblings('.dtcDisplayArea')",
             button: ".next()"
         });

         $("#<%=txtDOJ.ClientID %>").dynDateTime({
             //        $("#TextBox2").dynDateTime({

             showsTime: false,
             ifFormat: "%Y-%m-%d",
             //            ifFormat: "%Y/%m/%d %H:%M",
             daFormat: "%l;%M %p, %e %m, %Y",
             align: "BR",
             electric: false,
             singleClick: false,
             displayArea: ".siblings('.dtcDisplayArea')",
             button: ".next()"
         });

             });

     
</script>

this is working fine before adding autocomplete textbox code as follows

<link href="Styles/jquery-ui.1.8.1.css" rel="stylesheet" type="text/css" />
    <script src="Scripts/jquery.min.1.4.2.js" type="text/javascript"></script>
    <script src="Scripts/jquery-ui.min.1.8.1.js" type="text/javascript"></script>

<script type="text/javascript">
    $(document).ready(function () {
        SearchText();
    });
    function SearchText() {
        $(".autosuggest").autocomplete({
            source: function (request, response) {
                $.ajax({
                    type: "POST",
                    contentType: "application/json; charset=utf-8",
                    url: "frmUserMaster.aspx/GetAutoCompleteData",
                    data: "{'location':'" + document.getElementById('<%=txtLocation.ClientID%>').value + "'}",
                    dataType: "json",
                    success: function (data) {
                        response(data.d);
                    },
                    error: function (result) {
                        alert("Error");
                    }
                });
            }
        });
    }
</script>

Both are working fine separate web pages but when i am going to add on same page then it gives above error.
Please help me.