LAUNCH EXCEL
:::::::::::::::::::::::::::::::

declare
	appl_name varchar2(255);
	
begin
	if  
		:global.application_id is not null then
		message ('Application is already running');
	else
		 appl_name := 'C:\Program Files\Microsoft Office\OFFICE11\EXCEL.EXE';
		:global.application_id := dde.app_begin(appl_name, dde.app_mode_normal);
	end if;
	
	exception
		when 
		dde.dde_app_failure then
		  message ('Could not lanch application for DDE operations');
		  raise form_trigger_failure;
		  
		when others then
		  message('Error: '||to_char(sqlcode)||' '||sqlerrm);
		  raise form_trigger_failure;
		  
		end;

OPEN CHANNEL
::::::::::::::::::::::::::::::::::::::
begin
	if  
		:global.channel_id is not null then
		message ('Communication channel has already been established');
	elsif
		:global.application_id is null then
		message ('The application has to be launched first');
	else
		:global.channel_id := dde.initiate('EXCEL','BOOK1');
	end if;
	
	exception
		when 
		dde.dde_init_failed then
		  message ('Could not initialize DDE communication channel');
		  raise form_trigger_failure;
		  
	when 
		dde.dmlerr_no_conv_established then
		  message ('Could not established DDE communication channel');
		  raise form_trigger_failure;
		  
		  
		when others then
		  message('Error: '||to_char(sqlcode)||' '||sqlerrm);
		  raise form_trigger_failure;
		  
		end;
 
EXIT EXCEL
::::::::::::::::::::::::::::::::::::::::::
declare
	application_ID PLS_INTEGER;
	
begin
	if  
		:global.application_id is null then
		message ('Cannot shutdown application not initiated by this application');
	else
		application_id := to_number(:global.application_id);
		dde.app_focus(application_id);
		dde.app_end(application_id);
		:global.application_id := null;
		:global.channel_id := null;
	end if;
	
	exception
		when 
		dde.dde_app_not_found then
		  message ('Could not find applications for DDE opeartions');
		  raise form_trigger_failure;
		  
		when others then
		  message('Error: '||to_char(sqlcode)||' '||sqlerrm);
		  raise form_trigger_failure;
		  
		end;