storing sum val in the field via javascript

Dear Team,

i am trying to store the sum of 6 field in the answer filed , on real time the i am able to see the value after clicking on the calculate but when the process end and  gose to other person . we are not able to see the sum value, here is the java script which is done from my side kindly let me out who to store the value.

<script>
function MYBONUS(){
var a,b,c,d,e,f,g;
a=Number(document.getElementById("BONUS_ITEMS_1").value);
b=Number(document.getElementById("BONUS_ITEMS_2").value);
c=Number(document.getElementById("BONUS_ITEMS_3").value);
d=Number(document.getElementById("BONUS_ITEMS_4").value);
e=Number(document.getElementById("BONUS_ITEMS_5").value);
f=Number(document.getElementById("BONUS_ITEMS_6").value);
g= (a + b + c + d + e + f) / 6;
document.getElementById("Score_B").value= g.toFixed(2);
}
</script>

<button type="button" onclick="MYBONUS()">Click Here Bones Rate</button>