通过 JavaScript 禁用按键事件

I need to disable shift keypress event in my site by using JavaScript or any other method. Below is my code:

$(document).ready(function() {
document.onkeydown = checkKeycode
function checkKeycode(e) {
    var keycode;
    if (window.event) {
        keycode = window.event.keyCode;
    }
    else if (e) {
        keycode = e.which;
    }
    //alert(keycode);
    if (keycode == 16) {
        alert(keycode);
        return false;
    }
  }
});

// bind an event listener to the keydown event on the window
window.addEventListener('keydown', function (event) {

    // if the keyCode is 16 ( shift key was pressed )
    if (event.keyCode === 16) {

        // prevent default behaviour
        event.preventDefault();

        return false;
    }

});