// JavaScript Document
// --------------------------------------------------------------------------- //
// <div id="oImg" 
// style="position: absolute; z-index: 100; top: 0; left: 0; width: 97px; height: 97px;">
// <img src="pop/AD20070928.JPG" border="0" /></div>
// --------------------------------------------------------------------------- //

	var floatImg = document.getElementById("oImg");
	var delay = 10; //控制每次执行间隔的时间，做越大移动得越慢；
	var speed = 1; //控制每次执行移动的距离，值越大移动得越快；
	var flagX = 0;
	var flagY = 0;

	function toPixel(str1) {
		//该函数用于去掉数值后面的px，并将之转化为数字。
		var oldLen = str1.length;
		var newLen = oldLen - 2;
		
		str2 = str1.slice(0, newLen);
		str3 = parseInt(str2);
		
		return str3;
	}
	
	function flowImg() {
		var bWidth = document.body.clientWidth;
		var bHeight = document.body.clientHeight;
		var bLeft = document.body.scrollLeft;
		var bTop = document.body.scrollTop;
		 
		var iWidth = floatImg.offsetWidth;
		var iHeight = floatImg.offsetHeight;
		var iLeft = toPixel(floatImg.style.left);
		var iTop = toPixel(floatImg.style.top);
	  
		//下面一段控制横向移动
		if(iLeft < (bWidth - iWidth) && flagX == 0) {
			floatImg.style.left = (iLeft + speed) + "px";
		}
		else if(iLeft >= (bWidth - iWidth) && flagX ==0) {
			flagX = 1;
		}
		else if(iLeft > 0 && flagX == 1) {
			floatImg.style.left = (iLeft - speed) + "px";
		}
		else if(0 >= iLeft && flagX == 1) {
			flagX = 0;
		}
	
		//下面一段控制纵向移动
		if(iTop < (bHeight - iHeight) && flagY == 0) {
			floatImg.style.top = (iTop + speed) + "px";
		}
		else if(iTop >= (bHeight - iHeight) && flagY ==0) {
			flagY = 1;
		}
		else if(iTop > 0 && flagY == 1) {
			floatImg.style.top = (iTop - speed) + "px";
		}
		else if(0 >= iTop && flagY == 1) {
			flagY = 0;
		}
	}

	var imgInterval = setInterval("flowImg()", delay);

	function start() {
		
		floatImg.style.visibility = "visible";

		floatImg.onmouseover = function() {
			clearInterval(imgInterval);
		}
		floatImg.onmouseout = function() {
			imgInterval = setInterval("flowImg()", delay);
		}
	}
	start();