Question

How to disable asp:TextBox on client-side click on HTML checkbox or server-side asp:CheckBox using JavaScript?

<script type="text/javascript" language="javascript">
    function enableTextbox() {
        // ?
    }
</script>

<table>
    <tr>
        <td>
            <input id="checkTake" onclick="enableTextbox" title="Take?" />
        </td>
    </tr>
    <tr>
        <td>
            <asp:TextBox runat="server" ID="txtCommission" />
        </td>
    </tr>
</table>

Answer 1

<script type="text/javascript" language="javascript">
    function enableTextbox(checkbox) {
        document.getElementById('<%= txtCommission.ClientID %>').disabled = !document.getElementById(checkbox).checked;
    }
</script>

<table>
    <tr>
        <asp:CheckBox runat="server" ID="checkTake" onclick="enableTextbox(this.id)" Checked="true" Text="Take?" />
    </tr>
    <tr>
        <td>
            <asp:TextBox runat="server" ID="txtCommission" MaxLength="8" CssClass="right" />
        </td>
    </tr>
</table>