Couldn't be because of browser differences. I have tested in Chrome aswell. Could it be an error in my code? When I press the check box, the textbox is suppose to be disabled. this doesn't have so far. Here is the code I have:
I put the script on the top of the section of the page. 

Form name : frmPost

```
 <script type="text/javascript">
      function enabledisable() {
                if (document.getElementById("ePrice").checked) {    
                    document.frmPost.txtPrice.disabled=false;
                } else {
                    document.frmPost.txtPrice.disabled=true;
                }
            }​
    </script>

<input type="text" name="txtPrice" id="txtPrice" size="5">
<input type="checkbox" id="ePrice" name="ePrice"  onclick="enabledisable()"/>

```