Controlling outputpanel with JavaScript

panel.page

<apex:page showHeader="false" StandardController="Account">
<script>
	function changevalue(input) {
		value = input.options[input.selectedIndex].value;
		if(value == 'Customer - Channel') {
			document.getElementById('{!$Component.myform.mypanel}').style.display = 'none';
		} else {
			document.getElementById('{!$Component.myform.mypanel}').style.display = 'block';
		}
	}
</script>
<apex:form id="myform">
	<apex:inputField id="type" value="{!Account.Type}" onchange="changevalue(document.getElementById('{!$Component.type}'));" />
	<apex:outputPanel id="mypanel" layout="block">
		Hello World
	</apex:outputPanel>
</apex:form>
  
</apex:page>