trigger ownerValueSave on Branch__c(before update)
{
  if(trigger.isupdate)
  {
  for(Branch__c b:Trigger.new)
  {
     if(b.ownerId != Trigger.old[0].OwnerId)
     {
         User u = [select id,name from User where id=:Trigger.old[0].OwnerId];
        
         if(b.Owner2__c==null)
         {
             b.Owner2__c=b.Owner1__c;
         }
        
         if(b.Owner1__c==null)
         {
             b.Owner1__c=u.name;
        
         }
        
         else
        
        
          if(b.Owner2__c!=null)
         {
             b.Owner2__c= b.Owner1__c;
         }
        
         if(b.Owner1__c!=null)
         {
             b.Owner1__c=u.name;
         }
         
       
     }
  }
    
  }
}