The Listener evaluation result is captured into an internal variable, denoted by the ? symbol, each time you evaluate a command or code selection. You can access that value again with the ? question mark symbol. You can use the ? anywhere you use a variable name and MAXScript then evaluates it as the last Listener result. A common use is to capture the ? value into one of your own variables for later reuse, such as in the following statement:
x = ?