javascript - Open modal Popup on pageload event from server side using c# -

i want show modal popup on certain condition on page load event working.

this modalpopup:

<script type="text/javascript">     function openmodal(message, header, url) {         $('#mymodal').modal('show');         $('#lblmastermessage').html(header);         $('#lblmasterbodymessage').html(message);         $('#mymodal').on('hidden.bs.modal', function(e) {             if (url != '') {                 window.location = url;             }         });     } </script>  <asp:content id="content2" contentplaceholderid="bodycontentplaceholder" runat="server">     <div class="modal fade" id="mymodal" runat="server">         <div class="modal-dialog">             <div class="modal-content" style="width: 400px; margin: 0 auto;">                 <div class="modal-header" runat="server">                     <button type="button" class="close" data-dismiss="modal" aria-label="close">                                 <span aria-hidden="true">&times;</span></button>                     <h4 class="modal-title">                         <label id="lblmastermessage"></label>                     </h4>                 </div>                 <div class="modal-body">                     <label id="lblmasterbodymessage"></label>                 </div>                 <div class="modal-footer">                     <button type="button" class="btn btn-primary" data-dismiss="modal" runat="server">close</button>                 </div>             </div>         </div>     </div> </asp:content> 

calling modal popup backend:

protected void page_load(object sender, eventargs e) {      if (dt.rows.count > 0)      {          bindgrid();      }      else      {           string message = "files not generated!";           string header = "info";           scriptmanager.registerstartupscript(this, this.gettype(), "popup","openmodal('" + message + "','" + header + "','memberhomepage.aspx');", true);          //scriptmanager.registerstartupscript(this, this.gettype(), "popup", "alert('business operation files not generated!'); window.location ='memberhomepage.aspx';", true);      } } 

i not able show popup when condition satisfied. appreciated.

div represents modal runs on server, asp.net generate it's id. means that, when page rendered, modal's id not mymodal ctl00_content2_mymodal.

because of that, jquery cannont find div on line

$('#mymodal').modal('show'); 

change line

$('#<%= mymodal.clientid %>').modal('show'); 

or try access div class name, $(".modal")

edit: you'll have same problem other controls you're trying find id, such lblmastermessage, lblmasterbodymessage etc.