Miscellaneous Ellipsis or Em Dash?

[Bizkit]

Hey, I have a proofreading question.

When there is hesitation in the middle of word, should you use an ellipsis or em dash? I've seen it done both ways. Examples:

O...kay
O--kay

I've already asked my Edited Manga team about it, but I wanted to know what you guys think.

 

[Gradonil_Ral]

If you want to split the word without repeating it then it's Em Dash, otherwise it's Ellipsis.
In other words:
O--kay or O... Okay

Well, I think you can also use Em Dash (or a normal dash for that matter - it's not like many comic fonts can differentiate anyways) for a "repeating" word, but only if you want the pause to be much shorter.
O-Okay