Figure An error message

ImicfosoHVisual Basic

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Object required

End 1

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Error dialog boxes offer a few options: end the procedure, get help (such as it may be) with the problem, or enter break mode to debug the code. In the latter case, Excel will stop execution of the procedure at the offending code and highlight that code in yellow. We will discuss the process of debugging code a bit later.

Aside from encountering an error, there are several ways we can deliberately enter break mode for debugging purposes:

• Hit the Ctrl-Break key and choose Debug from the resulting dialog box.

• Include a Stop statement in the code, which causes Excel to enter break mode.

• Insert a breakpoint on an existing line of executable code. This is done by placing the cursor on that line and hitting the F9 function key (or using the Toggle Breakpoint option on the Debug menu). Excel will place a red dot in the left margin in front of that line and will stop execution when it reaches the line. You may enter more than one breakpoint in a procedure. This is generally preferred over using the Stop statement, because breakpoints are automatically removed when we close down the Visual Basic Editor, so we don't need to remember to remove them, as we do with Stop statements.

• Set a watch statement that causes Excel to enter break mode if a certain condition becomes true. We will discuss watch expressions a bit later.

To exit from Break mode, choose Reset from the Run menu.

Note that the caption in the title bar of the VBA IDE indicates which mode is currently active. The caption contains the word "[running]" when in run mode and "[break]" when in break mode.

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