ASCII字符显示

<p>
<font color="#FF99FF"><h2>你想查找统一字符吗? 请输入范围之内(0-60000):</h2></font>
<font color="#FF99FF">
备注: 中文字符(19900-41000) 非中文方字符(44400-55500) 其他字符(0-13500)</font><br/>
<font color="#FF99FF">(范围越大越卡......)</font>
<input type="text" id="txtOne" value="初始范围" onFocus="javascript:this.value=''">
<input type="text" id="txtTwo" value="结束范围" onFocus="javascript:this.value=''">
<input type="button" id="btnSearch" value="开始查找>>>" onClick="searchCode()"><br/>
<textarea name="textarea" id="txtA" cols="100" rows="30"></textarea>
</p>

<script language="javascript">
function searchCode()
{
        var numberOne=parseInt(document.getElementById("txtOne").value);
        var numberTwo=parseInt(document.getElementById("txtTwo").value);
        var numberThree=numberTwo-numberOne;
     if(numberThree<0||isNaN(numberOne)||isNaN(numberTwo))
     {
           alert("输入有误.请重新输入."); return;
     }
     else if(!isNaN(numberThree) && numberThree>=0)
     {
           document.getElementById("txtA").value=" ";
           for(var i=numberOne; i<=numberTwo; i++)
            {
            //alert(numberOne+"+"+numberTwo+"="+(numberTwo+numberOne));
            var stringCode=String.fromCharCode(i);
            document.getElementById("txtA").value+=stringCode;
           }
    }
}
</script>