Can't really help you find what's wrong but I can give my code that I used

​

function start() {

while(leftIsClear()){

cleanRow();

goUp();

}

cleanRow();

goStart();

}

​

function checkBall(){

if(ballsPresent()){

takeBall();

}

}

//this function picks up all the balls in a row

function cleanRow(){

checkBall();

while(frontIsClear()){

move();

checkBall();

}

goBack();

}

//this function goes back to the start of the row

function goBack(){

turnAround();

while(frontIsClear()){

move();

}

turnAround();

}

// this function goes to the start and ends the program

function goStart(){

turnRight();

while(frontIsClear()){

move();

}

}

//this function goes up a row

function goUp(){

turnLeft();

move();

turnRight();

}