Below is the code:
<script
language="javascript"
type="text/javascript">
window.onbeforeunload = function()
{
return "Are you sure want to close";
}
</script>
Above code will execute on
every postback. The alert message will appear on any click event like
button,links, hyperlinks etc
If we don't want this
message on click of buttons and links we have to implement below code :
<script
language="javascript"
type="text/javascript">
window.onload = function() {
var btnRelease = document.getElementById('<%=
btnRelease.ClientID %>');
//Find the button set
null value to click event and alert will not appear for that specific button
function setGlobal() {
window.onbeforeunload = null;
}
$(btnRelease).click(setGlobal);
// Alert will not appear for all links on the page
$('a').click(function()
{
window.onbeforeunload = null;
});
window.onbeforeunload = function()
{
return
'Are you sure you want to leave this page?';
};
};
}
</script>
Now alert/confirm message
will appear only on back button of browser.