calling javascript function on OnClientClick event of a Submit button

Question

In my asp.net page, I have three text boxes and one button.
First two text boxes are being used to get the value from the user and third one is being used to show the sum of first two boxes.

I am calling a javascript function to sum the values and show the result value on OnClientClick event of that BUTTON.

JS function is working fine but when I am pressing button to get the sum, it shows the result in third text box and just then the page is being post-back and result value becomes disappear from the third text box.

Why the post-back is called by the button?
I don't want page to be post-backed on click of submit button.

Any suggestion is appreciated.

Answer 1

<asp:Button ID="btnGet" runat="server" Text="Get" OnClick="btnGet_Click" OnClientClick="return callMethod();" />
<script type="text/javascript">
    function callMethod() {
        //your logic should be here and make sure your logic code note returing function
        return false;
}
</script>

Answer 2

The above solutions must work. However you can try this one:

OnClientClick="return SomeMethod();return false;"

and remove return statement from the method.