the problem is that you replaced the bing search form with your own:
<form id="form1" name="form1" method="post" action="http://www.ecommonwealthbank.com/results.php">
<label>
<input type="text" name="SearchCNB" id="SearchCNB" class="boxform" />
</label>
<label>
<input type="image" src="images/btn-go.gif" name="searchbtn" id="searchbtn" value="Submit" />
</label>
</form>
1) the method of the bing search form needs to be set to GET instead of post
2) The name of the text box in the form must be set to "Bing_query"
the form code should be:
<form id="form1" name="form1" method="get" action="http://www.ecommonwealthbank.com/results.php">
<label>
<input type="text" name="Bing_query" id="Bing_query" class="boxform" />
</label>
<label>
<input type="image" src="images/btn-go.gif" name="searchbtn" id="searchbtn" value="Submit" />
</label>
</form>