[Sooks]

Is there a lock button on the eris ?

[o2bnclemson]

Not to my knowledge. You can lock the screen by pressing the power button, but there isn't a designated "lock button". You can go into the security settings to do a "connect the dots" to make it less easy to unlock.

[IzelTokatl]

Correct, only power/end button to quickly turn the screen off and "lock it" to enable the security

Settings > Security > Set Unlock Pattern (then set your pattern)
Now set the check next to: Require Pattern and that will lock it out more.