Controlling outputpanel with Apex

extension.java

public with sharing class MyExtension {

	public Boolean showPanel {get; set;}
	public String inputValue {get; set;}
	
	public MyExtension(ApexPages.StandardController controller) {
		inputValue = '';
		showPanel = true;
		}

	public PageReference controlPanel() {
		showPanel = true;
		if(inputValue == 'Customer - Channel') {
			showPanel = false;
		}
		return null;
	}

	
}

outputpanel.xml

<apex:page showHeader="false" StandardController="Account" extensions="MyExtensions">
<apex:form id="myform">
	
	<apex:actionFunction action="{!controlPanel}" name="controlPanel" rerender="mypanel" >
		<apex:param name="inputValue" assignTo="{!inputValue}" value="" />
	</apex:actionFunction>
	
	<apex:inputField id="type" value="{!Account.Type}" onchange="controlPanel(document.getElementById('{!$Component.type}').options[document.getElementById('{!$Component.type}').selectedIndex].value);" />
	
	<apex:outputPanel id="mypanel" layout="block" >
		<apex:outputPanel rendered="{!showPanel}" ><apex:outputText value="{!inputValue}" />? {!showPanel}</apex:outputPanel>
	</apex:outputPanel>
</apex:form>
  
</apex:page>

try renaming from extension.class to extension.java and outputpanel.page to outputpanel.xml/html to get syntax coloring.

nifty!