Hello Andrea,
have a look at this.
Code:
{ rem input in drafting the macro
Macrostart:
v macro v Parameter
file_exists "path/filename"
Global variable: gv_file_existent
end rem }
DEFINE file_exists
PARAMETER File_1
LOCAL Default_file
LET Default_file "path/default_filename" {* Change *}
LET gv_file_existent 0
TRAP_ERROR
LOAD File_1
IF (CHECK_ERROR)
DISPLAY("File "+File_1+" not existent. Load Default File? Yes= any key | No= ESC ")
LOAD Default_file
ELSE
LET gv_file_existent 1
END_IF
END_DEFINE