下拉列表<option>中 ONMOUSEOVER显示注释
HTML：<select id="selects"><option selected="selected" id="brazil" onmouseover="tooltip(this)" onmouseout="nodisplay()" onclick="nodisplay()">巴西</option><option id="usa" onmouseover="tooltip(this)" onmouseout="nodisplay()" onclick="nodisplay()">美国</option><option id="chn" onmouseover="tooltip(this)" onmouseout="nodisplay()" onclick="nodisplay()">中华人民共和国</option></select><div id="tooltipBlock" style="position: block; display: none;">sdffds</div> JAVASCRIPT：var tip = document.getElementById("tooltipBlock");var selects = document.getElementById("selects");function tooltip(obj) {var x = selects.offsetLeft, y = obj.offsetTop, h = obj.offsetHeight, w = selects.offsetWidth;/*tip.style.width = w + "px"; （这部分是定义显示提示的块的宽度） */tip.style.marginLeft = x + w + "px";tip.style.marginTop = y - 30 + "px";tip.style.display = "block";tip.innerHTML = "这部分为程序传递（把数据库里相关国家资料传过来）";}function nodisplay() {tip.style.display = "none";}
