My quiz doesn't add the score and is keep on returning 0. Why?

// score
var counter = 0;


// question 1
var q1 = prompt("Is NYC in the United States?");
if (q1.toUpperCase === "YES"){
    counter += 1;
}

// question2
var q2 = prompt("Is Natasha Lyonne an actress?");
if (q2.toUpperCase === "YES"){
    counter += 1;
}

// question3
var q3 = prompt("Is the sun hot?");
if (q3.toUpperCase === "YES"){
    counter += 1;
}

// question4
var q4 = prompt("Is Berlin in England");
if (q1.toUpperCase === "NO"){
    counter += 1;
}

// question5
var q5 = prompt("How many fingers do you have?");
if (q1.toUpperCase === "TEN" || q1 === "10"){
    counter += 1;
}

// score to document    
document.write("You got " + counter + " questions right!");

// crown to document
if (counter === 5){
    document.write(" You got a gold crown!");
}   
else if (counter >= 3){
    document.write(" You got a silver crown!");
} else if (counter >= 1){
    document.write(" You got a bronze crown!");
} else (document.write(" Sorry, you don't get a crown! "))