You don't mention what version of ms-access you are using.
However, try creating a new database when you launch ms-access.
When you go file->new, you get two tabs, the 2nd tab usually has a bunch of
sample applications you can create/use.
In addition, there is a Northwind sample application on your office cd.
Hopefully, you installed it during your ms-access install. That application
has some invoice screens in it.
The idea here is to use a main form which is based on the invoice table. You
then create a one-to "many" relationship to display the invoice "details".
You then place a continues sub-form on the main invoice form. So, each
invoice has "many" details (in your case, you mention up to 5, but why make
any limit. If you design is correct, then it is no more work to have 2, or
20 entries for a give invoice.
As mentioned, get a copy of the Northwind database that came with ms-access,
as it has many sample screens, including some invoice ones. Also, check out
the database wizard (when you create a new database...try the 2nd tab called
"databases". There is some sample applications that invoice screens).
In addition, check out the following sample applications, again many have
sample invoice forms you can learn from.
http://search.officeupdate.microsoft.com/TemplateGallery/result.asp?qu=datab
ase
Continues forms are really what we use in ms-access to "replace" grids with.
Here is some sample screen shots of continues forms of mine:
http://www.attcanada.net/~kallal.msn/Articles/Grid.htm