javascript代码问题 --功能实现漫游的自由浮动层
- HTML code
<html><head> <script language = 'javascript'> function MM_swapImgRestore() { var i, x, a = document.MM_sr; for(i = 0; a && i<a.length && (x=a[i]) && x.oSrc; i++) { x.src = x.oSrc; } } function MM_preloadImages() { var d = document; if(d.images) { if(!d.MM_p) { d.MM_p = new Array(); } var i, j = d.MM_p.length, a = MM_preloadImages.arguments; for(i=0; i<a.length; i++) { if(a[i].indexOf("#") != 0) { d.MM_p[j] = new Image; d.MM_p[j++].src = a[i]; } } } } function MM_swapImage() { var i, j = 0, x, a = MM_swapImage.arguments; document.MM_sr = new Array; for(i=0; i<(a.length - 2); i += 3) { if((x = MM_findObj(a[i])) != null) { document.MM_sr[j++] = x; if(!x.oSrc) { x.oSrc = x.src; } x.src = a[i+2]; } } } </script></head><body> <script language = 'javascript'> var step = 2; var delay = 30; var height = 0; var Hoffset = 0; var Woffset = 0; var yon = 0; var kon = 0; var pause = true; var interval; var name = navigator.appName; if(name == "Microsoft Internet Explorer") { name = true; } else { name = false; } var xPos = 20; if(name) { var yPos = document.body.clientHeight; } else { var yPos = window.innerHeight; } function changePos() { if(name) { width = document.body.clientWidth; height = document.body.clinetHeight; Hoffset = img.offsetHeight; Woffset = img.offsetWidth; img.style.left = xPos + document.body.scrollLeft; img.style.top = yPos + document.body.scrollTop; } else { width = window.innerHeight; height = window.innerWidth; Hoffset = document.img.clip.height; Woffset = document.img.clip.width; document.img.pageY = yPos + window.pageYOffset; document.img.pageX = xPos + window.pageXOffset; } if(yon) { yPos = yPos + step; } else { yPos = yPos - step; } if(yPos < 0) { yon = 1; yPos = 0 } if(yPos >= (height - Hoffset)) { yon = 0; yPos = (height - Hoffset); } if(xon) { xPos = xPos + step; } else { xPos = xPos - step; } if(xPos < 0) { xon = 1; xPos = 0; } if(xPos >= (width - Woffset)) { xon = 0; xPos = (width - Woffset); } } function start() { if(name) { document.img.visibility = "visible"; } else { document.img.visibility = "visible"; } interval = setInterval('changePos()', delay); } function pauseResume() { if(pause) { clearInterval(interval); pause = false; } else { interval = setInterval('changePos()', delay); pause = true; } } start(); function stop() { clearInterval(interval); pause = false; } </script> <div id = "img" onMouseOver = "javascript:stop()" onMouseOut = "javascript:start()" style = "position:absolute; width:191px; height:55px; left:119px; top:4px"> <a href = "#" onMouseOut = "MM_swapImgRestore()" onMouseOver = "MM_swapImage('a02', '', 'picture.gif', 1)"></a> <a href = "#" onMouseOut = "MM_swapImgRestore()" onMouseOver = "MM_swapImage('Image_FL2', '', 'picture.gif', 1)"><img name = "Image_FL2" border = "0" src = "picture.gif" width = "180" height = "60" usemap = "#Image_FL2Map"> <map name = "Image_FL2Map"> <area shape = "rect" coords = "4, -4, 166, 28" href = "http://www.pku.edu.cn" target = "blank"> <area shape = "rect" coords = "6, 29, 164, 55" href = "http://www.tsinghua.edu.cn" target = "blank"> </map> </a> </div></body></html>
问题是：网页错误详细信息
用户代理: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET4.0C; .NET4.0E; InfoPath.2)
时间戳: Thu, 7 Apr 2011 01:55:39 UTC
消息: 'document.img' 为空或不是对象
行: 141
字符: 5
代码: 0
URI: file:///H:/wwwroot/www/Html/html69_漫游的自由浮动层/html69.html
最初我，没有加上document,只是img.visibility = "visible";
[解决办法]
document.getElementById("img")