Flash command

I found a tutorial which teach me how to load text (http://www.kirupa.com/developer/mx/externaldata.htm)…but there is a problem…most tutorial dont tell you where is the command in the Flash, it just tell you copy here or why use this command…or is there a way to trace which command?

One of them was loadText.load(“data.txt”);
It raw command was <not yet set>.load();
It have an object and parameter to input
Can anyone tell me where is this command located on Flash actionScripts?

THX