这代码错在哪？

[jianciwen]

<script language="javascript">
document.write("<div id=ad_hr style='position: absolute;width:120;top:300;left:5;visibility: visible;z-index: 1'><img scr=a.jpg onmouseover="window.scrollTo(1000,1000)"></div>");
</script>

这代码错在哪？？？为什么提示说少括号？

[shyslysky]

<script language="javascript">
document.write("<div id=ad_hr style='position: absolute;width:120;top:300;left:5;visibility: visible;z-index: 1'><img scr=a.jpg onmouseover="window.scrollTo(1000,1000)"></div>");
^ ^
</script>
引号混乱
<script language="javascript">
document.write("<div id=ad_hr style='position: absolute;width:120;top:300;left:5;visibility: visible;z-index: 1'><img scr=a.jpg onmouseover='window.scrollTo(1000,1000)'></div>");

[JK_10000]

双引号里套了双引号，导致错误

<script language="javascript">
document.write("<div id=ad_hr style='position: absolute;width:120;top:300;left:5;visibility: visible;z-index: 1'><img scr=a.jpg onmouseover='window.scrollTo(1000,1000)'></div>");
</script>