function quiz_grade() {
	
  if (document.getElementById && document.createTextNode) {	
	
	var q_answers = new Array()
	  q_answers[0] = "a"; // Answer for Question 1
	  q_answers[1] = "c"; // Answer for Question 2
	  q_answers[2] = "b"; // Answer for Question 3
	  q_answers[3] = "d"; // Answer for Question 4
	  q_answers[4] = "b"; // Answer for Question 5
	
	var num_right = 0;
	var num_wrong = 0;
	var the_score = 0;
	
	for (c=0; c<q_answers.length; c++) {
	  var q_n = "qu_" + (c+1);
      var q_a = document.getElementById(q_n).value;	
	  var q_a_exp = "^"+q_answers[c]+"$";
	  var q_a_tomatch = new RegExp(q_a_exp, "i");
	  var q_a_ismatch = q_a_tomatch.test(q_a);      	  
	  if (q_a_ismatch) {
	    num_right++;  
	  }
   	  else {
        num_wrong++;
	  }
    }
	
    the_score = Math.round(num_right/q_answers.length*100); 
    window.alert("You got "+num_right+"/"+q_answers.length+" correct for a score of "+the_score+"%.");	
    return false;	
   
  }
  
}