JS给gridview内的textbox赋值

通过js给gridview内的textbox赋值

<script type="text/javascript">
    function Check()
    {
        var tb=document.getElementById("<% = GridView1.ClientID %>");
        for (i=1;i<tb.rows.length;i++)
        {
            var cb = tb.rows[i].getElementsByTagName("input")[1];
            var textbox = tb.rows[i].getElementsByTagName("input")[0];
            if(cb.checked)
            {
                textbox.value="aaa";
                textbox.readOnly = false;
                textbox.style.backgroundColor="white";               
            }
            else
            {
                textbox.readOnly = true;
                textbox.style.backgroundColor="Gainsboro"; 
            }
        }
    }
</script>

点击checkbox后textbox内容改变