textarea 动态修改overflow属性问题

Question

<script type="text/javascript" language="javascript">
function TextAreaRow()
{
    var obj=document.getElementById("textarea");
    var rng=obj.createTextRange();
    var h=rng.boundingHeight;
    rng.move('character',1)
    var mh=rng.boundingHeight;

        var dd=(h/mh).toFixed(0);
        if(dd>7){
            [color=red]document.getElementById("textarea").style.overflow='';[/color]
        }

    document.getElementById("showRow").value=(h/mh).toFixed(0);
}
</script>

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行数：

当dd 大于7时修改textarea的overflow属性（[color=red]把style="overflow-y:hidden"这个属性去掉[/color]）？万分感谢！！！

Answer 1

[code="js"]document.getElementById("textarea").style.overflowY = "auto"; [/code]