I'm trying to find a restaurant called The Slug and Lettuce. Do you know where that is?
Yes it is in the centre area. 
I'd like to book it for 3 people at 16:45 on Saturday.
Certainly. I have booked you for Saturday at 16:45 for 3 people The Slug and Lettuce. Will there be anything else I can assist you with today? 
Could I get a reference number please?
I am sorry.  I went to get the reference number and now the system is not providing a reference number.  I can look for another restaurant.