If you are creating scripts using JavaScript, you can output messages to the JavaScript Console from Acrobat at run time by using the console.println method included with the JavaScript Object Model from Acrobat. When initiated, the console.println method displays a string value in the JavaScript Console. The string value can be a text message that you create for debugging purposes or the string value of fields or expressions.
For example, consider a scenario with a simple form design that contains a single numeric field (NumericField1) and a button (Button1). In this case, the following JavaScript script outputs a message displaying some text and the value currently displayed in the numeric field. By adding either the calculation or the script to the click event of the button object, you can interactively display the value of the numeric field in a new dialog box by clicking the button.
console.println(“The value is: ” + NumericField1.rawValue);
For more information about the console.println method and the JavaScript Object Model from Acrobat, see Developing Acrobat Applications Using JavaScript at http://www.adobe.com/go/learn_lc_AcrobatDeveloper (English only).
See also 

Providing debugging feedback using the JavaScript Console