In this text box you can enter a regular expression that describes those messages that you consider to be related to possible errors. TESTAR will apply this expression to each title of each widget on the screen. If it matches any widget’s title, TESTAR will report an error and save the sequence for later inspection. For example: Imagine you are looking for a critical message box with the title “A NullPointerException Exception has been thrown”. You could simply add the expression “.*NullPointerException.*” which will match any title that contains the word “NullPointerException” (the “.*” are placeholders for arbitrary characters). To learn more about Regular Expressions see http://en.wikipedia.org/wiki/Regular_Expression.