Disables the browser’s default behavior (response) for events (e.g. < A> Tag jump, etc.) and stop the event from propagating.

The implementation code

function stopEvent (evt) {
var evt = evt || window.event;
if (evt.preventDefault) {
evt.preventDefault();
evt.stopPropagation();
} else {
evt.returnValue = false;
evt.cancelBubble = true;
}
}

Only prevent the event from spreading (do not cancel the default behavior)

function stopEvent (evt) {
var evt = evt || window.event;
if (evt.stopPropagation) {
evt.stopPropagation();
} else {
evt.cancelBubble = true;
}
}

Only cancels the default behavior (does not prevent the event from propagating)

function stopEvent (evt) {
var evt = evt || window.event;
if (evt.preventDefault) {
evt.preventDefault();
} else {
evt.returnValue = false;
}
}