You invoke an error handler with the On Error statement, which comes in several varieties. Using the buttons on the screen shown here, you may choose the type of error handling that you need:

Instead of pressing a button you can use a corresponding keyboard action to check any On Error statement. The underlined symbols help you to do it. So you can press the underlined key only or a combination of [Alt+underlined key].

• On error Resume next. This statement informs Visual Basic that you want to resume at the statement immediately after the statement that generated the error, without any visible intervention from VB. Press R or Alt+R to implement this behaviour.

• On error GoTo 0. This statement disables any internal error handling of the routine. Visual Basic again traps subsequent errors. This statement also resets the value of the Error object, so if you need the values it contains, you must store away its properties. You can press 0.

• On error GoTo lDefaultError. This statement is used to cause Visual Basic to jump to the default error handler if an error occurs. This error handler is automatically inserted be the Error Guy (and it will be removed if you change the error handling). The Error handler simply calls the sub "DefaultError" that you may define according to your specific needs. A simple implementation could be as shown below:

Function DefaultError(strName) As VbMsgBoxResult DefaultError = MsgBox(Err.Description, vbAbortRetryIgnore + vbCritical + vbMsgBoxHelpButton, strName, Err.HelpFile, Err.HelpContext) End Function

This implementation shows a message box with the description of the error. You may press "Abort", "Retry" or "Ignore" at this message box. "Abort" will end the routine, where the error occurred, "Retry" will try the last statement (that caused the error) again and "Ignore" will simply skip that statement.

You may press D or Alt+D to implement this error handling.

• On error GoTo x. This statement allows you to build up your own error handling procedure. This may differ from the standard error handling procedure that error handling wizard inserts. The wizard is not able to insert, delete or alter these error-handling codes.

• On Error GoTo lExit. Using this option, the Error Guy will insert a label "lExit" at the end of your routine. If an error occurs, the code proceeds at that label. You may insert special clean-up instructions into your code after the "lExit" label. You can press E or Alt+E.

• No error handling. There is no error handling in the routine because YOU decided, that it should be as it is. O.K., we told you before, that it is good programming practice to include an error handling into every routine. But there is no rule without an exception. If you want to access Visual Basic's Err object, you shouldn't have any "On Error..." statement before, because all this statements (even "On Error GoTo 0") are clearing the Err object. Therefore we give you this option to tell the Error Guy, that you don't want this routine to contain an error handling. Press O or Alt+O to change to this case.

• Undefined error handling. This option tells, that you have got no error handle in this procedure and (in opposite to the former option) you didn't make the explicit decision to include none. You may press U or Alt+U to get this option.

If you change the type of error handle in the selected procedure blueshell Error Guy informs you about it and asks you for confirmation. An exception: If your routine has "Undefined error handling" no confirmation is necessary.

The current procedure of your application, in which you include an error handler, is presented in the textbox of the Error Guy form. That's how you can see the error handling code that you have inserted.

You can look through your entire project to be sure that all error handling is well defined. For this purpose you can use the Find function with all its options. You may read it on the next page.