Thank you so much for your help.
Here is what I have:

Purchase Order Form has:    Order ID-Auto number
                CustomerID-Number
                Employee ID-Number
                Order Date-Date/Time
                Purchase Order Number-Text
                And some other Misc fields

The Purchase Order Details Sub-Form has:    Order Detail ID-Auto-number
                           OrderID-Number                        NomenclatureID-Number
                           Nomenclature-Text
                           Part Number-Number
                           Quantity-Number
                           And some misc fields

In design view in the subform property sheet the Master/Child link is:
OrderID/OrderID

For each purchase order number, I may have five or six parts (nomenclature)
that I am ordering from the supplier (customer).  I need each purchase order
number to print in a report with just the items purchased under that Purchase
Order Number from that supplier (customer).  For Example:

Purchase Order: 7155-4380
Supplier (Customer): Ram Aircraft
Employee: Nancy
Shipping Method: UPS Ground

Purchase Order Details Subform:

Nomenclature:    Part Number        Quantity    Price    Line Total
Starter        Ms74887-020    1    $3000.00    $3000.00
Starter Clamp    MS12345-7     2    $3.50    $7.00
Starter Brush    MSabcdef-123    6    $10.00    $60.00

                Subtotal                   $3,067.00
                Tax        $214.69
                Order Total    $3281.69

End of Purchase Order 7155-4380

At this point I want to click on Preview Purchase Order Report and then
print. The Purchase Order Report should only print this purchase order
information.  When I advance to the next purchase order on the purchase order
form, i.e. 7156-4380 I want to do the same thing, only print the purchase
order report with the details of purchase order 7156-4380.  I hope this makes
sense.

1.    Purchase Order Number ifield is the one I need to limit, I think.
2.    I am not sure I understand the question so here goes.  On the Purchase
Order form there is a text box for purchase order number that I manually
input each time.  The name of the form is Add an Order and Details.  I would
prefer to call it Purchase Order Form, but at this point I am afraid to
change it.  If you can get me going in the right direction I am sure I can
figure out how to change the name so as not to screw up any underlying forms,
tables, etc.  
3.    Data Type of the Purchase Order number is text.
4.    I currently have a command button on the form that opens the preview
report.  On the properties page of the common button on the click event it
says [Embedded Macro].  If there is a better way, I am all ears…

I started reviewing your site after the last post you did.  Very interesting
reading.  I will continue to read it.  As I said before, I am pretty new at
this stuff so there is a learning curve.  I have learned a lot so far and
this site is amazing.  And I plan to continue reading.

Thank you so very much for all your help.