You should never do that. https://www.irt.org/script/311.htm
By the way, you may just warn the user using window.onbeforeunload
.
You can-not actually disable browser back button. And there is no event for capturing the back button click.
If it is really necessary you can do something like that:
(function (global) {
var _extra_hash = "!";
var noBack = function () {
global.location.href += "#";
global.setTimeout(function () {
global.location.href += _extra_hash;
}, 50);
};
global.onhashchange = function () {
if (global.location.hash !== _extra_hash) {
global.location.hash = _extra_hash;
}
};
global.onload = function () {
noBack();
// this is for disabling backspace on page except on input fields and textarea..
/*document.body.onkeydown = function (e) {
var elm = e.target.nodeName.toLowerCase();
if (e.which === 8 && (elm !== 'input' && elm !== 'textarea')) {
e.preventDefault();
}
// stopping event bubbling up the DOM tree..
e.stopPropagation();
};*/
}
})(window);
But the user can still kill the tab. Anyway, It is generally a bad idea overriding the default behavior of web browser.