var ImgW = "288px";
var ImgH = "200px";

document.write('<div id="floatImg" style="top:90px;left:0px;position:absolute;z-index:101;width:288px;height:200px;"><object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000"' +
                                                                                   'codebase="http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=7,0,0,0"' +
                                                                                   'width="288" height="200" id="Untitled-1" align="middle">' +
                                                                                 '<param name="wmode" value="transparent">' +
                                                                                '<param name="allowScriptAccess" value="sameDomain" />' +
                                                                                '<param name="movie" value="images/ad/ad_fly.swf" />' +
                                                                                '<param name="quality" value="high" />' +
                                                                                '<param name="bgcolor" value="#ffffff" />' +
                                                                                '</object></div>')

var floatImg = document.getElementById("floatImg");
var delay = 30; //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.documentElement.clientHeight == 0) ? document.body.clientHeight : document.documentElement.clientHeight);
    var bLeft = document.documentElement.scrollLeft;
    var bTop = ((document.documentElement.scrollTop == 0) ? document.body.scrollTop : document.documentElement.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);
floatImg.onmouseover = function() { clearInterval(imgInterval); }
floatImg.onmouseout = function() { imgInterval = setInterval("flowImg()", delay); }