Angu2, yes, they got help in the past by other songwriters. But the word HELP is the keyword. They always wrote and will write their songs by themselves, but it's of course okay when they hear the opinion of someone else and take some ideas.

According to the Backstage newsletter (Jon's letter in it) Everyday was written a few days after Sept. 11 in Nashville by Richie and Jon. They propably showed the song to this Swedish songwriter and he gave his ideas and they changed this and that. That's why he is credited as a songwriter, too.