I have a code in java script for disabling a button until the checkbox is checked. It doesn't grey this out in bootstrap. It just shows the button.

```
https://jsfiddle.net/soljohnston777/wg00ymg8/

```

Bootstrap attempt to make this work:

Modal / Html:

```
    <div id="example" class="modal hide fade in" style="display: none; ">  
    <div class="modal-header">  
    <a class="close" data-dismiss="modal">×</a>  
    <h3>Terms and Conditions</h3>  
    </div>  
        <div class="modal-body"> 

        <h4>Text in a modal <input type="checkbox" required="required" id="myCheck"></h4>

        <p>You can add some text here.</p> 
    <div class="checkbox">
    <input id="check" name="checkbox" type="checkbox">
    <label for="check">Some Text Here</label>
    </div>          
        </div>  
    <div class="modal-footer">  

    <input type="submit" name="" class="btn" id="btncheck" value="I Agree" />
    <a href="#" class="btn btn-success" data-dismiss="modal">Close</a>  
    </div>  
</div>  

```

Without the Modal classes:

<http://www.bootply.com/nV8ShsZUH5>

What am I doing wrong?