I don't understand why this code won't work.  I just want a comments box to appear if you select that the customer refused the survey...

<apex:actionRegion >
                <apex:pageBlockSectionItem >
                    <apex:outputLabel value="Customer refused survey?" for="refused"/>
                    <apex:InputField value="{!Post_Install_Survey__c.Refused__c}" id="refused" required="true">
                    <apex:actionSupport event="onChange" reRender="rfcomments"/>
                    </apex:InputField>
                </apex:pageBlockSectionItem>
                </apex:actionRegion>
                <apex:InputField value="{!Post_Install_Survey__c.Services__c}"/>
                <apex:pageblockSectionItem id="rfcomments">
                <apex:InputField value="{!Post_Install_Survey__c.Refused_Comments__c}" rendered="{!Post_Install_Survey__c.Refused__c == 'Yes'}"/>
                </apex:pageblockSectionItem>

I don't understand why this code won't work.  I just want a comments box to appear if you select that the customer refused the survey...

<apex:actionRegion >
                <apex:pageBlockSectionItem >
                    <apex:outputLabel value="Customer refused survey?" for="refused"/>
                    <apex:InputField value="{!Post_Install_Survey__c.Refused__c}" id="refused" required="true">
                    <apex:actionSupport event="onChange" reRender="rfcomments"/>
                    </apex:InputField>
                </apex:pageBlockSectionItem>
                </apex:actionRegion>
                <apex:InputField value="{!Post_Install_Survey__c.Services__c}"/>
                <apex:pageblockSectionItem id="rfcomments">
                <apex:InputField value="{!Post_Install_Survey__c.Refused_Comments__c}" rendered="{!Post_Install_Survey__c.Refused__c == 'Yes'}"/>
                </apex:pageblockSectionItem>