FireFox下 event is not defined.

解决FireFox下event is not defined.

onkeydown="doSearch(event)"

function doSearch(e){

    var code;
    if (!e) var  e = window.event;
    if (e.keyCode) code = e.keyCode;
    else if (e.which) code = e.which;
    if(code==13){
        //do something.
    }

}

参考http://www.quirksmode.org/js/events_properties.html