code for how to send username and password to their email in ios after registering account

code for how to send username and password to their email in ios after
registering account

IN .xib file i will have
First Name :----------- Last Name :------------ email id :------------
pincode :------------
-----------------
register button
-----------------
After clicking registration button the user name and password should be
send to the given email id in the form.
I need code for this please.