Why cant i change the fillamount with a variable of a other script ?

hey @ all, i've made a Ngui image for a healthbar and i tried to change its fillamount ( horizontal filled ) by a static variable declared in my "New_Health"Script.
public class New_Health : MonoBehavior
public static float = my_value;
void Update()
my_value = curhealth / maxhealth; (here its correctly calculated)

then i want to get this value in my healthbar script like this :
public class healthbar : MonoBehavior
public float fillvalue;

void Update ()
New_Health.my_value = fillvalue;
Image image = GetComponent<<Image>();
image.fillamount = fillvalue;(but not here)
its always 1 although its becoming less with every hit in the script above and i get no errors !
if i dont set it as a static i get : no object reference for the non static ......
so many tuts, so many time but i still havent found a solution by my own. i'm (still) new to this so i would be very very glad if someone could help me to fix this.