Flash MX 2004.
prompt(promptMsg [,text])
promptMsg A string to display in the Prompt dialog box (limited to 256 characters in Mac OS X).
text An optional string to display as a default value for the text field.
The string the user typed if the user clicks OK; null if the user clicks Cancel.
Method; displays a prompt and optional text in a modal Alert dialog box, along with OK and Cancel buttons.
The following example prompts the user to enter a user name. If the user types a name and clicks OK, the name appears in the Output panel.
var userName = prompt("Enter user name", "Type user name here");
fl.trace(userName);