Multiple gift certificates can be bought at one time, as long as they are all of the same value and will have the same message associated with them (up to 255 characters).
During checkout process, the gift certificate will be handled as a free shipping item. So the shipping form will not be displayed in shopcustomer.asp
If more than one gift certificate is to be purchased, your customer needs to enter the first person’s details into the To Name and Email fields, then the additional recipients into the box at the bottom of the page. The additional recipients can only be specified by their email addresses, not their name as well.