My program won't start

var score = 0;
var firstAnswer = prompt ("What is the complementary color for red?");
var secondAnswer = prompt ("Is black a color?");
var thirdAnswer = prompt("What color do perfect complementary colors mixed together should produce?");
var fourthAnswer = prompt ("What is the base for acrylic paint?");
var fifthAnswer = prompt("How many colors are in the rainbow?");
if (firstAnswer.toLowerCase === "green") {
    score +=1;
}
if (secondAnswer.toLowerCase === "no" || secondAnswer.toLowerCase === "false"){
    score +=1;
}
if (thirdAnswer.toLowerCase === "gray") {
    score +=1;
}
if (fourthAnswer.toLowerCase === "water") {
    score +=1;
}
if (fifthAnswer.toLowerCase === "seven" || fifthAnswer === "7") {
    score +=1;
}
document.write("<p> You scored " + score + " questions right!</p>");
if (score === 5) {
    alert("Congratulations!, you get a gold crown!");
}
elseif (score < 5 && score >= 3 ) {
    alert ("You get a silver crown!");
}
elseif (score < 3 && score >= 1) {
    alert ("You get a bronze crown"); 
}
else {
    alert ("Please try again");
}