The answers to my questions continually come back as incorrect, any ideas why?

console.log("start program");
var Answer= false;
var correct= 0;
var questions= 5;
var questionsLeft=  "(There are " + questions + "questions left)";

// questions
var japFlag= prompt("What color is the cirlce on japanese flag");
if (japFlag.toUpperCase=== "red") {alert("correct");
                                     correct+= 1;}
else {alert("incorrect");}

questions-= 1;
questionsLeft="(There are " + questions + "questions left)";


var usFlag= prompt("what color is the stars on  the U.S. flag?");
if (usFlag.toUpperCase=== "white"){alert("correct");
                                    correct+= 1; }
else{alert("incorrect");}

questions-= 1;
questionsLeft= "(There are " + questions + "questions left)";


var japCity= prompt("What is japan's largest city?");
if (japCity.toUpperCase=== "tokyo") {alert("correct");
                                      correct+= 1;}
else {alert("incorrect");}

questions-= 1
questionLeft= "(There are " +questions + "questions left)";


var usCity= prompt("What is largest in the U.S.?");
if (usCity.toUpperCase=== "los angeles"||usCity==="la") {alert("correct");
                                                           correct+= 1;}
else {alert("incorrect");} 

questions-= 1;
questionsLeft="(There are " + questions + "questions left)";


var largeState= prompt("What is the largest state in the U.S.?");
if (largeState.toUpperCase==="alaska") {alert("correct");
                                          correct+= 1;}
else {alert("incorrect");}

questions-= 1;
questionsLeft="(There are " + questions + "questions left)";

//output results
alert("You got "+ correct + " out of 5 questions");


if( correct===5) {alert("you earned a gold crown");}
else if(correct >= 3) {alert("you earned a silver crown");}
else if(correct >= 1) {alert("you earned a bronze crown");}
else {alert("you didn't earn a crown");}