第一階段Javascript 字串搜尋

最近有人要求要幫忙寫頁面商品搜尋, 可是對方卻沒有給任何的key value, 所以這根本沒辦法從SQL搜尋，非常的悲劇又令人頭痛, 以下範例為字串搜尋，但只從字串第一位搜尋, 正在改良:

<p>搜尋目標</p>
<div id="se"></div>

<div class="sea">1231231321</div>
<div class="sea">222</div>
<div class="sea">333</div>
<div class="sea">441</div>
<div class="sea">552</div>
<div class="sea">666</div>
<input type="text" id="search" />

<script type="text/javascript">
    write();

    function write() {
        document.getElementById("se").innerHTML = document.getElementById("search").value;
        ans();
        setTimeout("write()", 100);
    }

    function ans() {
        for (var i = 0; i <= document.getElementsByClassName("sea").length - 1; i++) {
            if (document.getElementsByClassName("sea")[i].innerHTML.toString().substring(0, document.getElementById('search').value.length) == document.getElementById('search').value && document.getElementById('search').value != "") {
                console.log("found" + document.getElementsByClassName("sea")[i].innerHTML.toString().substring(0, document.getElementById('search').value.length));
            }

            if (document.getElementsByClassName("sea")[i].innerHTML.toString().substring(0, document.getElementById('search').value.length) != document.getElementById('search').value) {
                document.getElementsByClassName("sea")[i].style.display = "none";
            } else {
                document.getElementsByClassName("sea")[i].style.display = "";
            }
        }
    }
</script>

以上只搜尋節點，隱藏其他內容