enable textbox with checkbox checked with javascript

HEllo - I am trying to enable/disable textbox when checkbox is checked (enable) or unchecked (disable). WIth the piece of code i have nothing is happening once the checkbox is checked/unchecked. Here is what I have:

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="AssociationInfo.ascx.cs" Inherits="Administration.Modules.AssociationInfo" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="asp" %>
     <script type=开发者_高级运维"text/javascript" language="javascript">
        function enableTextBox() {
            window.onload = function () {
                var check = document.getElementById("chkAssociation");
                check.onchange = function () {
                    if (this.checked == true)
                        document.getElementById("txtAddress").disabled = false;
                    else
                        document.getElementById("txtAddress").disabled = true;
                };
            };
        }
    </script>

    <div>
    <h2>Association Info</h2>
    <br />

      <asp:CheckBox Checked="false" ID="chkAssociation" runat="server" />&nbsp;&nbsp;
       <asp:TextBox ID="txtAddress" Text="Test" runat="server" />
    </div>

The code is in web user control. Could that be reason why is not working correctly?

Thanks for helping

Thanks everyone for the help in advance, Laziale

---

Please turn of AutoPostBack.

<asp:CheckBox Checked="false" 
              OnChange="javascript:enableTextBox();" 
              ID="chkAssociation" 
              runat="server" />

EDIT: Try this code,

<script type="text/javascript">
        window.onload = function() {
            var check = document.getElementById("<%=chkAssociation.ClientID %>");
            check.onchange = function() {
                if (this.checked == true)
                    document.getElementById("<%=txtAddress.ClientID %>").disabled = false;
                else
                    document.getElementById("<%=txtAddress.ClientID %>").disabled = true;
            };
        };
</script>        

<asp:CheckBox  Checked="false"   ID="chkAssociation" runat="server" />
<asp:TextBox ID="txtAddress" Enabled="false" Text="Test" runat="server" />

---

Try "onclick" instead of "onchange" - I believe that's what you're looking for.

---

Check this

1.If Checkbox is Checked then the Textbox be Disable

<script type="text/javascript">
function enableDisable(bEnable, textBoxID)
{
     document.getElementById(textBoxID).disabled = bEnable

}
</script>


 <asp:TextBox ID="t1" Text="" runat="server" />
<asp:CheckBox ID="chk1" Checked="false" onclick="enableDisable(this.checked, 't1');" runat="server" />

2.If Checkbox is Checked then the Textbox be Enable

 <script type="text/javascript">
function enableDisable(bEnable, textBoxID)
{
     document.getElementById(textBoxID).disabled = !bEnable

}
</script>
        <asp:TextBox ID="t1" Text="" runat="server" />
        <asp:CheckBox ID="chk1" Checked="true" onclick="enableDisable(this.checked, 't1');" runat="server" />