fix for #81314.

reword the dialog you get when you exit while sending mail.
r=varada, sr=bienvenu.  thanks to stephend@netscape.com for the initial patch.

mailnews/compose/resources/content/MsgComposeCommands.js

@@ -1570,7 +1570,16 @@ function ComposeCanClose()
       {
         var promptTitle = gComposeMsgsBundle.getString("quitComposeWindowTitle");
         var promptMsg = gComposeMsgsBundle.getString("quitComposeWindowMessage");
-        if (gPromptService.confirm(window, promptTitle, promptMsg))
+        var quitButtonLabel = gComposeMsgsBundle.getString("quitComposeWindowQuitButtonLabel");
+        var waitButtonLabel = gComposeMsgsBundle.getString("quitComposeWindowWaitButtonLabel");
+
+        var result = {value:0};
+        gPromptService.confirmEx(window, promptTitle, promptMsg,
+          (gPromptService.BUTTON_TITLE_IS_STRING*gPromptService.BUTTON_POS_0) +
+          (gPromptService.BUTTON_TITLE_IS_STRING*gPromptService.BUTTON_POS_1),
+          waitButtonLabel, quitButtonLabel, null, null, {value:0}, result);
+
+        if (result.value == 1)
           {
             msgCompose.abort();
             return true;

mailnews/compose/resources/locale/en-US/composeMsgs.properties

@@ -195,8 +195,9 @@ subjectDlogMessage=You did not specify a subject for this message. If you would
 attachPageDlogTitle=Please specify a location to attach
 attachPageDlogMessage=Web Page (URL):
 
-## String used by the Initialization Error dialog, %1$s will be replaced by the error string
+## String used by the Initialization Error dialog
 initErrorDlogTitle=Message Compose
+## LOCALIZATION NOTE (initErrorDlogMessage): %1$s will be replaced by the error string.  do not translate \n
 initErrorDlogMessage=An error occurred while creating a message compose window. Please try again.\n%1$s
 
 ## Strings used by Save as Draft/Template dialog
@@ -206,5 +207,8 @@ SaveDialogMsg=Your message has been saved to the folder %1$S on %2$S.
 CheckMsg=Do not show me this dialog box again.
 
 ## Strings used by prompt when Quitting while in progress
-quitComposeWindowTitle=Close Mail Window
-quitComposeWindowMessage=There is mail being sent, do you want to quit now or cancel and quit after the mail is sent?
+quitComposeWindowTitle=Sending Message
+## LOCALIZATION NOTE (quitComposeWindowMessage): don't translate \n
+quitComposeWindowMessage=Mail is currently in the process of sending a message.\nWould you like to wait until the message has been sent before quitting or quit now?
+quitComposeWindowQuitButtonLabel=Quit
+quitComposeWindowWaitButtonLabel=Wait