function navTopMouseOver(navDivId, navTopAClass, navTopAOverClass){var collTopANodes = document.getElementById(navDivId).getElementsByTagName("a");for (var x = 0; x < collTopANodes.length; x++) {collTopANodes[x].onmouseover = function(){collTopANodes[x].className = navTopAOverClass;}();}}我想實(shí)現(xiàn)在節(jié)點(diǎn)對象上鼠標(biāo)進(jìn)入就改變class，但是這段代碼在網(wǎng)頁一加載，我還沒有讓鼠標(biāo)經(jīng)過，它的class就變了，而且不循環(huán)，只有第一個節(jié)點(diǎn)對象會變，這是怎么回事？