firefox英文字符串不自动换行问题的解决方法

<script type="text/javascript">

function toBreakWord(intLen, id){

var obj=document.getElementById(id);

var strContent=obj.innerHTML;

var strTemp="";

while(strContent.length>intLen){

strTemp+=strContent.substr(0,intLen)+"<br>";

strContent=strContent.substr(intLen,strContent.length);

}

strTemp+= strContent;

obj.innerHTML=strTemp;

}

</script>

<div id=content2
></div>

<script language='javascript'>toBreakWord(18, content2
);</script>