Servo/potentiometer interference?

I am using an Arduino Mega 2560 with this (http://www.ebay.com/itm/381044529782?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT) sensor board to control 5 servos using five potentiometer (I am building a Robot). Sometimes when I move One potentiometer to move one servo, other servos are somehow affected and will move slightly.

Can anyone tell me why and what to do to fix the problem?

I attached my code: ES and CRS are digital servos which is why I used writeMicroseconds (seems to work better with digital servos)
My code isn’t very well commented out since I am both a beginner and It is not very complex

Robot_Arm_Mk8_Arm2_Kevin.ino (1.38 KB)

Please post your code