What are the parameters used in SAPScript functions? | SAP-ABAP

1.  OPEN_FORM--  this module name of the layout set which is to be opened is mentioned.
Parameters used in this functional module are:
?    Exporting
?    Form
?    Language
2.  WRITE__FORM--. is used to display the data. Element name and window is specified.
Parameters used in this functional module are:
?    Exporting
?    Element                   
?   Window
3. CLOSE_FORM-- is used to close the form after displaying or printing the data.