"Take for granted" and "Welcome to Chicago"

Can someone help me with 2 translations where I cannot seem to get a good translation from in dict.leo.org

Take For Granted.
Can someone give me the term for "take for granted" in the context of underappreciating someone or something. Like how one will take his wife for granted or how people take their eyesight and good health for granted.

"Welcome to Chicago"
Is saying "Wilkommen ZU Chicago" the best way to say this?

Thanks
Chi-town

Willkommen IN Chicago...not zu...

The other one I don't know unfortunately...

EDIT: Taking for granted...jemanden/etwas als selbstverstaendlich nehmen perhaps?

"als selbstverständlich hinnehmen" or "als Selbstverständlichkeit betrachten"
Just what is the context? Maybe it needs a less literal translation.
EDIT: I would say "Herzlich willkommen in Chicago"; willkommen hardly ever stands alone in this context.

"Jemanden/etwas für selbstverständlich halten" or what sarabyrd said (all are correct), and also what sarabyrd and camlough said (Herzlich willkommen in Chicago).

Thanks everyone.

The "take for granted" I mean, is like when someone is begining to lose their eyesight and they plead for everyone to never take your eyesight for granted. Or when we hear about someone having an affair, they say they have done so because their mate took them for granted.

chi-town

"Blindheit kann vorkommen, willst du diese schöne Hund jetzt kaufen? Kostet nur €2000."

now now sk