as it will avoid the overhead of processing an events file the error list window will be created at initialization and the window handle will be stored in the global control block gcb the main control block used by the ide editor a pointer in a structure pointed to by the error list 39 s window words will point to the start of the error list data structure if the error list is empty the 34 display error list 34 action will be grayed out and the error list window will not be in the window list if the error list is ever displayed the error list window will be added to the window list when the error list is closed it will be removed from the window list the basic structure of the information needed by the ide for displaying the error list window is illustrated in the data structure shown in fig4 file 1 has a pointer to file 2 and file 2 has a pointer back to file 1 and so forth file information is kept in a doubly linked list for each file a pointer points to the first error in the file used when writing out the error list window file information is kept in a file information record fir each error in the file is kept in a doubly linked list with a pointer back to the corresponding file this pointer is used when 34 find error 34 is selected to determine which file the message is located in error information is kept in an error information record eir the information in this data structure is used to fill the error list window the error list window itself is implemented as a.