解决onmouseout冒泡（兼容浏览器）

function hideBox(event,obj) {
    var event = event || window.event;
    var oBox = obj;
    var oTarget = event.relatedTarget || event.toElement;
    if (contains(oBox, oTarget)) {
        return;
    } else {
        obj.style.display = "none";
    }
}

function contains(refNode, otherNode) {
    if (typeof refNode.contains == "function" || "object") {
        return refNode.contains(otherNode);
    } else {
        return !!(refNode.compareDocumentPosition(otherNode) & 16);
    }
}

<div id="hidediv" onmouseout="hideBox(event,this);" ></div>