Function: try()

Evaluates an Expression and returns its value unless an error has occurred. If an error occurs, the error value is placed into an internal variable called _error and the 2nd Expression is evaluated.

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The first expression tries to convert crm.total to a number. If the conversion fails, the reason for the failure is stored in the internal variable _error. This value, along with a value from the in pipe is stored in the user defined $SysError variable, and a value of -1 is returned.

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