I have a Droid Razr that i have recently got that has the Android software on it. On my old Nokia phone, it wouldnt lock unless i physically pulled the slider down. The screen would go black after 15 seconds if i didnt lock it, but i could touch it and it would light back up. How can i do this on my Droid? I've tried a few different apps and they just keep my screen on all the time, which obviously wears the battery down. I just want it so i can touch the screen and use it, without physically pressing the lock but and unlocking. Thank you in advance.