Just another bizarre thing I do for fun...
"okay" is an alternate spelling of the word "OK". According to the oxford dictionary of current English, "OK" originated in the US "probably [as an] abbreviation of 'orl (or "oll") korrect', [a] jocular form of 'all correct'".
that's not true. OK came from a US president's campaign. Old ??? was his nick name and implied that everything was ok (for lack of a better word).