function search() {
var input, filter, found, table, tr, td, i, j;
input = document.getElementById("myInput");
filter = input.value.toUpperCase();
table = document.getElementById("myTable");
table.style.display = "block";
tr = table.getElementsByTagName("tr");
for (i = 0; i < tr.length; i++) {
    td = tr[i].getElementsByTagName("td");
    for (j = 0; j < td.length; j++) {
        if (td[j].innerHTML.toUpperCase().indexOf(filter) > -1) {
            found = true;
        }
    }
    if (found) {
        tr[i].style.display = "";
        found = false;
    } else if (!tr[i].id.match('^tableHeader')) {
        tr[i].style.display = "none";
    }
}

<table id="myTable">
            <tr>
                {% for key, value in list.items() %}
                <td>{{ key|e }</td>
                <td id="name">{{ value|e }}</td>
                <td>
                    <form class="form-signin ajax" action="/signIn" method="post" data-replace="#res" role="form">
                        <input type="checkbox" name="watchlist" value="Watchlist" onclick="writeToCell (this.id)" id="{{ key|e }}">
                    </form>
                </td>
            </tr>
            {% endfor %}
        </table>