Using the standard controllers, you can set variables or SObject variables by passing in data from a record. Let's look at an example that sets the initial value of VarT_NewOppID to the Visualforce expression {!Opportunity.Id} when the interview starts, as shown in the following sample code:

<apex:page Standardcontroller="Opportunity"> 
  <flow:interview name="Copying_the_record_followers" > 
    <apex:param name="VarT_NewOppID" value="{!Opportunity.Id}"/> 
  </flow:interview> 
</apex:page>

With the standard controller, you can set the value of variables and SObject variables.