Basisi of deciding whether CST/VAT has to be calculated

I  am registered dealer in AP . I am making a sale to a Customer whose Invoice address is AP but delivery address is Delhi . Will CST be calculated . I reckon  the deciding factor for  deciding whether CST / VAT is the movement of goods . If Delivery address is a state which is different from the state from which the movement of goods commences then it is a interstate sale and CST will be calculated . This has nothing to do with the Invoice address state

Another scenario can be taken wherein a registered dealer in AP is making movement of goods to a Customer in Delhi  but the Invoice for the same is sent to Customers AP address . In this scenario only VAT AP will be calculated since there is only an Intrastate movement of goods 

The CST Act  says that : 

A sale or purchase of goods shall be deemed to take place in the course of