You need something in test_access.js that refers to the component with test.js on it - then call GetComponent on that - or just assign it in the inspector:
#test_access.js#
var theOtherObject : test;
function Start() {
theOtherObject.SCORE = "1";
}
Or:
var otherObject : GameObject;
function Start() {
otherObject.GetComponent(test).SCORE = "1";
}
Please remember naming conventions really help - your scripts (and their inherent classes should start with a capital). Variables should start with a lower case letter and then be Camel case. All upper case implies a constant or preprocessor defined value.