How to refer to a TextBox in JavaScript inside an ASP.NET control? -

i have asp.net control text fields , checkbox. modify checkbox state using javascript based on values present in text fields after page load.

how can reliably read text field values in javascript? saw this answer didn't help:

<asp:textbox text='<%# bind("something") %>' id="txtsomething" runat="server"> </asp:textbox>  <script type="text/javascript">     alert($('#<%= txtsomething.clientid %>').val()); </script> 

this doesn't work; vs tells me "txtsomething not declared. may inaccessible due protection level."

how else can refer text box in javascript?

you can try client id of control contains text box , after search in children input id contains text box server id

<script type="text/javascript">     alert($('#<%= parentcontrol.clientid %>').find("input[id$='txtsomething']").val()); </script> 

as option can do:

<script type="text/javascript">     alert($('#<%= (parentcontrol.findcontrol("txtsomething")).clientid %>').val()); </script>