动态计算还能够输入多少字节的表单（纯script，请吧昨天的精华替换成这个吧，那个中文也算1字节

<script language=javascript>
function strlength(str){
    var l=str.length;
    var n=l
    for (var i=0;i<l;i++)
    {
        if (str.charcodeat(i)<0||str.charcodeat(i)>255) n++
    }
    return n        
}

function changebyte(value,length){
    var l=strlength(value)
    if (l<=length) {
        if (document.all!=null) document.all(“byte”).innertext=”还可以输入”+(length-l)+”字节”
    }
    else
    {
        document.all(“byte”).innertext=”输入字节数超出范围”
    }
    return true
}

function changebyte1(value,length){
    var l=strlength(value)
    if (l<=length) {
        if (document.all!=null) document.all(“byte1″).innertext=”还可以输入”+(length-l)+”字节”
    }
    else
    {
        document.all(“byte1″).innertext=”输入字节数超出范围”
    }
    return true
}

function changebyte2(value,length){
    var l=strlength(value)
    if (l<=length) {
        if (document.all!=null) document.all(“byte2″).innertext=”还可以输入”+(length-l)+”字节”
    }
    else
    {
        document.all(“byte2″).innertext=”输入字节数超出范围”
    }
    return true
}
</script>
<form method=”post” name=test onsubmit=”return checkdata()” action=””>
<textarea onkeydown=”return changebyte1(document.test.icqcontent.value,198)” onkeyup=”return changebyte1(document.test.icqcontent.value,198)” name=icqcontent cols=40 rows=”3″></textarea>
<span id=byte1><script language=javascript>changebyte1(document.test.icqcontent.value,198);</script></span>
</form>