VAT on cash sales in restaurant

[Nuara Valsecchi]

Hi,

probably an other silly question but thank in advance for your help...

Trying to understand how to calculate the VAT (IVA, BTW...whatever the  
name in the different countries) for a small business like a restaurant.
If I write an invoice to a customer the tax (in liability) is  
calculated automatically and the amount is written in the correct  
account when posted.
My wonder though is for the payment received from the customers in the  
restaurant paying cash. There are 2 different taxes applied (6 and 19%  
depending on food or alcohol) but I am not sure where and how I am  
supposed to account for the payments.
Should I write them as Income (i.e. sales)? if yes, is there a way to  
have the tax calculated directly or would I have to split the  
transaction and enter them manually???

thanks in advance