通常，您可以比较
client[Height|Width]与
scroll[Height|Width]以便检测到此情况…
…但是，当可见溢出时，这些值将相同。因此，检测程序必须考虑到这一点：
// Determines if the passed element is overflowing its bounds,// either vertically or horizontally.// Will temporarily modify the "overflow" style to detect this// if necessary.function checkOverflow(el){ var curOverflow = el.style.overflow; if ( !curOverflow || curOverflow === "visible" ) el.style.overflow = "hidden"; var isOverflowing = el.clientWidth < el.scrollWidth || el.clientHeight < el.scrollHeight; el.style.overflow = curOverflow; return isOverflowing;}在FF3，FF40.0.2，IE6，Chrome 0.2.149.30中进行了测试。
