Javascript condition - show an element if checkbox condition is true

I'm new in Javascript and Jquery, so I'm having a problem.

Here is a code which checks if three checkboxes are checked, and at last - condition- if all of those three are checked, show an html element.

$('input[class^="class"]').click(function() {    var $this = $(this); 
    if ($this.is(".class1")) {
        if ($this.is(":checked")) {
            $(".class1").not($this).prop({ disabled: true, checked: false });
            $(".class").prop("checked", true);
            setTimeout(function() { $('#2').click(); }, 1000); //oncheck moves to the next question
            var questionOne = 1;
        } else {
            $(".class1").prop("disabled", false);
        }
    }

   if($this.is(".class2")) {
        if ($this.is(":checked")) {
            $(".class2").not($this).prop({ disabled: true, checked: false });
            $(".class").prop("checked", true);
            setTimeout(function() { $('#3').click(); }, 1000);
            var questionTwo = 1;
        } else {
            $(".class2").prop("disabled", false);
        }
    }

   if($this.is(".class3")) {
        if ($this.is(":checked")) {
            $(".class3").not($this).prop({ disabled: true, checked: false });
            $(".class").prop("checked", true);
            setTimeout(function() { $('#4').click(); }, 1000);
            var questionThree = 1;
        } else {
            $(".class3").prop("disabled", false);
        }
    }

 if(questionOne = 1 && questionTwo = 1 && questionThree = 1) { alert("alert on Page load"); }                                             
}); 

I guess the problem is either in setting variables or in the last condition.

Thanks in advance! Best Regards, Joni