codebar/tutorials

Hi everyone,
I'm practising Javascript with exercises from two books. They explain not to use global variables but then in the examples, they use them very often. So I'd like to rewrite this example from Javascript Head First, so that it's all done with locals. But my version is not completely right...So I'd appreciate your comments. Thanks in advance.

The code from the book:

var avatar = "generic";
var skill = 1.0;
var pointsPerLevel = 1000;
var userPoints = 2008;

function getAvatar(points){
var level = points / pointsPerLevel;
if (level == 1) {
return "Teddy bear";
} else if (level == 1) {
return "Cat";
} else if (level >= 2) {
return "Gorilla";
}
};
function updatePoints(bonus, newPoints) {
var i = 0;
while(i<bonus){
newPoints = newPoints + skill * bonus;
i = i + 1;
}
return newPoints + userPoints;
}
userPoints = updatePoints(2,100);
avatar = getAvatar(2112);

My version with locals - but gives me undefined...

function getAvatar(points){
var pointsPerLevel = 1000;
var level = points / pointsPerLevel;
if (level == 1) {
return "Teddy bear";
} else if (level == 1) {
return "Cat";
} else if (level >= 2) {
return "Gorilla";
}
};
function updatePoints(bonus, newPoints) {
var i = 0;
var skill = 1.0;
var userPoints = 2008;
while(i<bonus){
newPoints = newPoints + skill * bonus;
i = i + 1;
}
return newPoints + userPoints;
}

function init(){
userPoints = updatePoints(2,100);
var avatar = getAvatar(2112);}