How to prevent postback on asp button while displaying a popup using JQuery

Question

I have the following ItemTemplate in my GridView:

Answer 1

Put it out on the tag or <%: Html.BeginForm %> tag

Answer 2

Actually you have not showed up the implementation of your method myfunction(), in case the myfunction() method have any syntactical error then the OnClientClick event will be void and it will post-back/submit the form to the server.

Try to remove the call from OnClientClick and just implement your logic at jquery on click event by using class selector as follows

$(document).ready(function () {
        $(".btnSearch").click(function (e) {
            e.preventDefault();
            alert($(this).val() + " Clicked"); // you can put your method mymethod() here 
            // you can put youe popup logic here

            return false; 

        });
    });

You can also see this example of js fiddle

Answer 3

OnClientClick="return myfunction(); 

function myfunction(){
// you can put youe popup logic here 

    return false;

}

Using like this your button never do post back.