Newbie with a Servo

I have an arduino uno, with a servo but am unable to get the servo to turn. I am using this simple code:
#include <Servo.h>
Servo servo1;
void setup() {
servo1.attach(14); //analog pin 0
}
void loop() {
servo1.write(100);
}

The servo is a 4.8-6V, I have ground (brown) to the uno GND and the 5V to Servo (Red) and the PWM 14 pin to the control (yellow) on the servo,

When I run the sketch, nothing happens. I thought that maybe the 5 volts was not enough so I build a 6v Battery pack out of 4 AA batteries, which provides 6V, this I connected to the Ground(brown) and the 6V to the servo (red), and tried to run the posted code but nothing happened. When I connect the 6V the servo does jump for a moment.

Any help, or visible problems with my setup?
Thanks

You don't have a delay. Use a delay(100); at the end of the loop() function. The little 'jump' when a servo is powered is normal. You could try a normal digital pin.

When using an external supply for the servo (good idea), you should connect both GND's. Else the control signal has no reference and won't do anything (see my signature).

Add delay(500) and an other line sending the servo to an other position, followed by an other delay(500). This way should see the servo move back and forth each second.

Thanks connecting the ground to both worked.