<img id=img1 src="http://expert.csdn.net/images/csdn.gif">
<script>
document.all.img1.style.borderStyle='solid';
document.all.img1.style.borderColor='blue';
</script>
<script>
document.all.img1.style.borderStyle='solid';
document.all.img1.style.borderColor='blue';
</script>
<script language=javascript>
document.all.img1.style.border = '1px solid red';
</script>
建议直接在html里加边框,
<img style="border:1 solid blue">