文本框(input)获取焦点(onfocus)时样式改变的实现方法

<script type="text/javascript">
<!--
function focusInput(focusClass, normalClass) {
    var elements = document.getElementsByTagName("input");
    for (var i=0; i < elements.length; i++) {
        if (elements[i].type != "button" && elements[i].type != "submit" && elements[i].type != "reset") {
            elements[i].onfocus = function() { this.className = focusClass; };
            elements[i].onblur = function() { this.className = normalClass||''; };
        }
    }
}
window.onload = function () {
    focusInput('focusInput', 'normalInput');
}
//-->
</script>