try<head>
<script language="javascript">
var img=new Image()
img.src="file:///c:/1.jpg"
onload=function(){
if (img.complete){
document.getElementById("change").style.display=""
}
}
</script>
</head><body>
<img src="file:///c:/1.jpg" id="change" style="display:none"/>
</body>
<script language="javascript">
var img=new Image()
img.src="file:///c:/1.jpg"
onload=function(){
if (img.complete){
document.getElementById("change").style.display=""
}
}
</script>
</head><body>
<img src="file:///c:/1.jpg" id="change" style="display:none"/>
</body>
setTimeout(function(){
var img = new Image();
img.onerror = function(){
//移除的处理
}
img.onload = function(){
//替换图片
}
img.src = "地址?rnd"+ Date().getTime();
},1000);
}不检测图片是否己经改变,只要有图片就替换