Some parameters for Built-in functions and procedures have predefined default values. If you do not provide an actual parameter for a formal parameter, Oracle Forms uses the default value defined for that parameter. Consider the procedure CALL_FORM, which invokes a new form module while keeping the current form module active. The following example shows the syntax for the CALL_FORM procedure:
Open_Form(form_name,activate_mode,session_mode);
The default parameter values defined for the activate_mode and session_mode parameters are the constants ACTIVATE and NO_SESSION, respectively.
When you invoke OPEN_FORM without parameters, Oracle Forms uses the default parameters implicitly:
Open_Form('order_entry');
It is always acceptable to enter the default parameter values if you want to do so for the sake of clarity. The following procedure calls are equivalent; the first requires fewer keystrokes, but the second is more descriptive:
Open_Form('order_entry');
Open_Form('order_entry',ACTIVATE,NO_SESSION);