Hi Antonio Patino...
The approval process is used in companies in which the standard work procedure requires an approval from a manager or senior member before employees can generate certain documents, for example, purchase orders. The manager defines the stages of the approval process and the templates used, this includes which:
- Employees' documents require approval.
- Employees can authorize documents.
- Documents are part of the approval process.
A document’s approval process begins when an employee (who is the originator of the document) adds the document as a draft in SAP Business One. A request for approval is sent via an internal message to the manager or senior member (authorizer) required to approve the document (according to the definitions in SAP Business One). These internal messages support the approval process, by informing originators and authorizers about document status and any changes.
A document's approval process ends when the originator receives final approval and adds the document as a regular document.
Process
- A manager identifies the approval processes required by the company.
- When a document is created that is subject to the approval process:
The originator receives a message indicating that an approval is required before the document can be saved as a regular document.
- The document is saved as a draft.
Check with the link
http://www.youtube.com/watch?v=29tjevnyuPk
http://help.sap.com/saphelp_sbo882/helpdata/en/45/06dab4d8696c30e10000000a114a6b/content.htm
Hope helpful 
Regards
Kennedy