1. A GUI (Graphical User Interface) supported specification method for form field extraction and database mapping in a computer system, the method comprising: converting a form file into a fixed electronic document format by using a GUI, wherein the GUI is used to specify the form file and one or more conversion parameters; extracting one or more fields from the fixed electronic document format by using the GUI, wherein the GUI is used to specify the fields to be extracted; and mapping the fields onto a database schema by using a GUI, wherein a GUI is used to specify the mapping between the fields and the database schema.