How do I go into a message conversation My friends iPhone 4 will not provide notification when I send a message from my iPhone 5.  All other messages from all other contacts will notify him when they text him.  I was researching the issue and found the "just go into the go into the conversation -> details -> and toggle the do not disturb switch."  How does he do that.  We can find no "details" or "do not disturb" toggle.
Whilst viewing a list of messages (conversation view), tap the blue i in a circle at the top-right of the screen. This is the conversation details view, where one can change conversation settings.