Error messages displayed in the Build Output window as a result of using the Check Edit Window or Check Selection tools can be used to locate the statement causing the error in the program.
Double-clicking the error message activates the Visual LISP text editor window and places the cursor at the beginning of the statement that caused the error. The entire expression is also highlighted. The following illustration shows the results of double-clicking an error in the Build Output window.
The above example code displays an error as a result of the last princ statement in the if statement. The if statement only allows two arguments: the statement to execute if the expression is true, and the statement to execute if the expression is false. The last princ statement, which is used in this program to cause a quiet exit, belongs after the close parenthesis that currently follows it. If you move the statement to the correct location and check the program again, the code should pass as error-free.