sessions.page

<apex:page controller="SessionController">
  <apex:form >
		<apex:commandButton value="Add Session" action="{!createNewSession}"
			id="btnAddSession" />
		<apex:commandButton value="Save" action="{!save}" id="btnSave"
			style="display:none" />
		<apex:commandButton value="Cancel" action="{!cancel}" id="btnCancel"
			style="display:none" reRender="PanelId" />
		<apex:pageBlock >
			<apex:pageBlockTable value="{!lstSessions}" var="Session"
				rendered="{!lstSessions.size > 0}" id="pbt">
				<apex:column headerValue="{!$ObjectType.Session__c.Fields.Session_Status__c.Label}">
					<apex:outputField value="{!Session.Session_Status__c}" />
				</apex:column>
				<apex:column headerValue="{!$ObjectType.Session__c.Fields.GL_Department__c.Label}">
					<apex:outputField value="{!Session.GL_Department__c}" />
				</apex:column>
				<apex:column headerValue="{!$ObjectType.Session__c.Fields.Quantity__c.Label}">
					<apex:actionRegion >
						<table border="0" id="table_quantity">
							<tr>
								<td border="0"><apex:outputField value="{!Session.Quantity__c}">
									<apex:inlineEditSupport event="ondblClick"
										showOnEdit="btnSave,btnCancel" hideOnEdit="btnAddSession"
										rendered="{!Session.Session_Status__c != 'Booked'}" />
								</apex:outputField></td>
							</tr>
						</table>
					</apex:actionRegion>
				</apex:column>
				<apex:column headerValue="{!$ObjectType.Session__c.Fields.Unit_Cost__c.Label}">
					<apex:actionRegion >
						<table border="0" id="table_unit_cost">
							<tr>
								<td border="0"><apex:outputField value="{!Session.Unit_Cost__c}">
									<apex:inlineEditSupport event="ondblClick"
										showOnEdit="btnSave,btnCancel" hideOnEdit="btnAddSession"
										rendered="{!Session.Session_Status__c != 'Booked'}" />
								</apex:outputField></td>
							</tr>
						</table>
					</apex:actionRegion>
				</apex:column>
			</apex:pageBlockTable>
		</apex:pageBlock>
	</apex:form>
</apex:page>

SessionsController.cls

public with sharing class SessionController {
  
	public List<Session__c> lstSessions {get;set;}
	
	public SessionController()
	{
		lstSessions = [select Id, Session_Status__c, GL_Department__c, Quantity__c, Unit_Cost__c from Session__c];	
	}
	
	public PageReference createNewSession()
	{
		return null;
	}
	public PageReference save()
	{
		return null;
	}
	public PageReference cancel()
	{
		return null;
	}
}