Thank you for your reply.  The form I would like to do this on is for Purchase Orders.  Users fill out the form and then it undergoes an approval process.  I need a way to reference back to each form with a unique ID Number that only applies to 1 Purchase Order form.  Our purchase order numbers are in sequential order, so ideally I would like to have that number on the form itself.  

I need to count the total instances of when a purchase order is submitted.  Perhaps when the user hits the "submit" button on the form, a number field on the form is populated with  a number + 1, so that number only applies to that purchase order form.  

A couple of ideas:

Use the form instance number in a field or on the form when you save it to the repository; this is a unique number.

or

Add a sequential number to the form during processing.  From the from run a workflow that generates this number in SQL.  You could do a lookup after this workflow to bring the number back to the form (version 9) or use the Workflow input / output fields in Version 10.  An SQL sequential number generator is outlined in: https://www.laserfiche.com/support/webhelp/Laserfiche/10/en-US/administration/#../Subsystems/Forms/Content/Lookup-Rules.htm?Highlight=increment