Javascript generating an error, used to work

I have a pop up window that has terms and conditions for customers. There are two buttons on the bottom (I Agree, I Disagree). This window opens when the credit card number changes in the order form.

The Agree button closed the pop up and returns to the order page. The Disagree closes the pop up, and returns them to the pricelist window.

The code was working fine until I made some changes to my site. I added submneus to an existing flyout with Dreaweaver and Fireworks. This was done on a template and then updated to all my pages.

Now when I test the form I get the following error
'window,opener.top' is not an object on the Disagree button.
The Agree button now generates a dialog box asking me if I want to close the window. This did not happen before either

Any Ideas on what happened???

Here is the code:

<td><img src="images/agree.gif" width="100" height="30" onClick="javascript:window.close()"></td>
<td><img src="images/disagr.gif" width="100" height="30" border="0" onClick="javascript:window.opener.top.location.href='pricelist.htm';
window.top.close();">

I think something in Dreaweaver is not documented. I went into my page opened up the behavior, reslected my tems page, saved and everything works. Not sure why but glad it is.

Thanks for taking the time to look at my problem, if you have any ideas on what may have happened I'd be glad to hear them.