JS+CSS实现一个气泡提示框_javascript技巧

function showToolTip(e,text){ 
if(document.all)e = event; 
var obj = document.getElementById('bubble_tooltip'); 
var obj2 = document.getElementById('bubble_tooltip_content'); 
obj2.innerHTML = text; 
var st = Math.max(document.body.scrollTop,document.documentElement.scrollTop); 
if(navigator.userAgent.toLowerCase().indexOf('safari')>=0)st=0; 
var leftPos = e.clientX + 20; //clientX 事件属性返回当事件被触发时鼠标指针相对于浏览器页面（或客户区）的水平坐标 
if(leftPos<0)leftPos = 0; 
obj.style.left = leftPos + 'px'; 
obj.style.top = e.clientY + st + 'px'; 
obj.style.display = 'block'; 
fadeIn(obj,5,100); 
} 
function hideToolTip() 
{ 
var obj = document.getElementById('bubble_tooltip'); 
//obj.style.display = 'none'; 
fadeOut(obj,5,0); 
} 
//设置元素透明度,透明度值按IE规则计,即0~100 
function SetOpacity(ev, v){ 
ev.filters ? ev.style.filter = 'alpha(opacity=' + v + ')' : ev.style.opacity = v / 100; 
} 
//淡入效果(含淡入到指定透明度) 
function fadeIn(elem, speed, opacity){ 
/* 
* 参数说明 
* elem==>需要淡入的元素 
* speed==>淡入速度,正整数(可选) 
* opacity==>淡入到指定的透明度,0~100(可选) 
*/ 
speed = speed || 20; 
opacity = opacity || 100; 
//显示元素,并将元素值为0透明度(不可见) 
elem.style.display = 'block'; 
SetOpacity(elem, 0); 
//初始化透明度变化值为0 
var val = 0; 
//循环将透明值以2递增,即淡入效果 
(function(){ 
SetOpacity(elem, val); 
val += 5; 
if (val <= opacity) { 
setTimeout(arguments.callee, speed) 
} 
})(); 
} 
//淡出效果(含淡出到指定透明度) 
function fadeOut(elem, speed, opacity){ 
/* 
* 参数说明 
* elem==>需要淡入的元素 
* speed==>淡入速度,正整数(可选) 
* opacity==>淡入到指定的透明度,0~100(可选) 
*/ 
speed = speed || 20; 
opacity = opacity || 0; 
//初始化透明度变化值为0 
var val = 100; 
//循环将透明值以5递减,即淡出效果 
(function(){ 
SetOpacity(elem, val); 
val -= 5; 
if (val >= opacity) { 
setTimeout(arguments.callee, speed); 
}else if (val < 0) { 
//元素透明度为0后隐藏元素 
elem.style.display = 'none'; 
} 
})(); 
}