js禁止enter回车事件方法

document.onkeydown = function(e) {
var ev = (typeof event!= 'undefined') ? window.event : e;
if(ev.keyCode == 13) {
return false;
}
}

$(window).keydown( function(e) {
var key = window.event?e.keyCode:e.which;
if(key.toString() == "13"){
return false;
}
});