Couldn't be more obvious, the Character Name element is where you indicate who's talking.
Not much to say, except that you want to be consistent. Don't call a character MR. JONES in one part of the script and DAVE somewhere else (with Scriptware, it's easy to check to see if you've done this; you just look at the Character List and see who's on it... then you can change the wrong ones with just a keystroke or two).
If you have two characters speaking simultaneously and saying the same thing, you can make a character name out of both of their names. For example:BOB AND RHONDA Wait! Stop!
If you had two characters saying different things at the same time, use Dual-Column Dialogue.
Try to avoid using Names that look similar to avoid confusing the reader. Some suggest that you don't have two characters who have names that start with the same letter for this same reason.
To introduce a Character in a mysterious way, by hearing her/his voice, without revealing who it is, call the character something like MAN'S VOICE or WOMAN'S VOICE. Since we're hearing but not seeing them, it would typically be: MAN'S VOICE (V.O) or WOMAN'S VOICE (O.S.). (You wouldn't underline the extension, that's happening because those are links). Then, in the Action, you can reveal to the reader that:...we see that the voice belongs to:MARTHA Hello, dear.
A Character Name is uppercase, 3.5" from the left edge of the page. There is one blank line before a Character Name.
With Scriptware, you can type a character name with just one keystroke!
If you're on a blank line, just press <Tab>. Scriptware will put the cursor in the Character Name position and pop up a box with every character name you've already typed.
If you just start typing, the one you want will appear (this usually takes just one keystroke). If you're typing a new name, just type it in; Scriptware automatically adds it to the list so you'll never have to type it again!
Once you've typed the Character Name, pressing <Enter> will put you in the right place to type Dialogue. Pressing <Tab> will set you up to enter an Extension.