multiple servos and pots

Tanks, my goal is to have all servos listen to all pots. But i'd like to control the direction of servos independently for each pot also. here is the new code:

// Controlling a servo position using a potentiometer (variable resistor)
// by Michal Rinott http://people.interaction-ivrea.it/m.rinott

#include <Servo.h>

Servo frontleft;
Servo rearleft;
Servo frontright;
Servo rearright;// create servo object to control a servo

int collectivestick = 0;
int elevatorstick = 1;
int aileronstick = 2;
int rudderstick = 3;// analog pin used to connect the potentiometer

int val; // variable to read the value from the analog pin
int val2;
int val3;
int val4;
int test;
int test2;
int test3;
int rudright;

void setup()
{
frontleft.attach(9); // attaches the servo on pin 9 to the servo object
frontright.attach(10);
rearleft.attach(11);
rearright.attach(12);
}

void loop()
{
val = analogRead(collectivestick); // reads the value of the potentiometer (value between 0 and 1023)
val2 = analogRead(aileronstick);
val3 = analogRead(elevatorstick);
val4 = analogRead(rudderstick);
test = analogRead(collectivestick);
test2 = analogRead(aileronstick);
test3 = analogRead(elevatorstick);
rudright = analogRead(rudderstick);

test = map(test, 0, 1023, 179, 0);
test2 = map(test2, 0, 1023, 179, 0);
test3 = map(test3, 0, 1023, 179, 0);
rudright = map(rudright, 0, 1023, 0, 89);
val2 = map(val2, 0, 1023, 0, 179);
val3 = map(val3, 0, 1023, 0, 179);
val4 = map(val4, 0, 1023, 89, 179);// scale it to use it with the servo (value between 0 and 180)
val = map(val, 0, 1023, 0, 179);

int mapval[]={
test,test2,test3,rudright,val2,val3,val4,val,
}; //array of variables for servo mapping

frontleft.write((val+val2+mapval[2])/3);
rearleft.write((mapval[1]+mapval[0]+mapval[2]+mapval[3])/4);
frontright.write((mapval[0]+val2+val3+mapval[3])/4);
rearright.write((mapval[1]+val+val3)/3); // sets the servo position according to the scaled value

delay(50); // waits for the servo to get there
}

I'm having trouble with the servos twitching and resting center positions at extremes. maybe my voltage is inconsistent.