How to use javascript function for HTML button?

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I have a html button and a hidden field like this

<button id="btnperfdel" runat="server" type="button" class="btn btn-outline-secondary" onclick="myconfirm"></button>
<asp:HiddenField ID="myanswer" runat="server" ClientIDMode="Static" />

and this is my script that i want to run

<script type = "text/javascript">
      function myconfirm() {

          var myanswer = document.getElementById("myanswer")

          if (confirm("Confirm Delete?")) {
              myanswer.value = "Yes"
          }
          else {
              myanswer.value = "No"
          }
      }

    </script>

and this is my background code

Protected Sub btnperfdel_ServerClick(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnperfdel.ServerClick

       If myanswer.Value = "Yes" Then
           'some random things
       Else
           ClientScript.RegisterStartupScript(Me.GetType(), "alert", "alert('You clicked Cancel')", True)
       End If
   End Sub

But the javascript is not firing for onclick event. I tried onclientclick but if only returns alert 'You clicked cancel'.

What I have tried:

I tried other javascripts also, but all returns false value for onclientclick event and for onclick event, it doesn't doing anything. I'm novice in javascript. Please,Can someone help me out?

Posted 26-Oct-21 22:39pm

Souvik Roy 2021

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Bob@work 27-Oct-21 18:18pm

You're trying to run a javascript triggered by a DOM even, but the button is controlled by the server. The button attribute runat="server" preempts the onclick="myconfirm" and treats the button like a server-side control, not part of the DOM.

Using your browser, right-click the button and inspect it. you'll see what the server is doing to the button code.

The asp page code:
<asp:button id="LoginButton" runat="server" commandname="Login" text="Log In" validationgroup="LoginUserValidationGroup">

will generate something like this on the user's browser:

< input type="submit" name="ctl00$MainContent$LoginUser$LoginButton" value="Log In" onclick="javascript:WebForm_DoPostBackWithOptions(new WebForm_PostBackOptions("ctl00$MainContent$LoginUser$LoginButton", "", true, "LoginUserValidationGroup", "", false, false))" id="ctl00_MainContent_LoginUser_LoginButton" >

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