请教个JS定位表格内元素的问题。

Question

<table id="mytable" border="2" style="border-color:Green;">
            <caption>读取表格内的文本框的值，输出 ABCDE</caption>
            <tr>
                <td><input type="text" name="TextBox" value="A" /></td>
                <td>&nbsp;NULL</td>
            </tr>
            <tr>
                <td><input type="text" name="TextBox" value="B" /></td>
                <td>&nbsp;NULL</td>
            </tr>
            <tr>
                <td><input type="text" name="TextBox" value="C" /></td>
                <td>&nbsp;NULL</td>
            </tr>
            <tr>
                <td><input type="text" name="TextBox" value="D" /></td>
                <td>&nbsp;NULL</td>
            </tr>
            <tr>
                <td><input type="text" name="TextBox" value="E" /></td>
                <td>&nbsp;NULL</td>
            </tr>
        </table>
<script>
tb = document.getElementById("mytable")
tb.rows[0].firstChild.firstChild.focus()
for(i=0;i<tb.rows.length;i++){
alert(tb.rows[i].firstChild.firstChild.value)
}
</script>

Answer 1

<script>
tb = document.getElementById("mytable")
tb.rows[0].firstChild.firstChild.focus()
for(i=0;i<tb.rows.length;i++){
alert(tb.rows[i].cells[0].firstChild.value)
}
</script>
可以用rows和cells定位行和列.