old_contents: function StudentSelectorChanged() {
  	if (getSelectedStudentOption().className.indexOf('not-admitted') === -1) {
  		document.querySelector('#remove_student').removeAttribute("disabled");
  		document.querySelector('#new_student_pw').removeAttribute("disabled");
  		document.querySelector('#new_student_pw_submit').removeAttribute("disabled");
  		document.querySelector('#admit_student').setAttribute("disabled", "disabled");
  	} else {
  		document.querySelector('#remove_student').removeAttribute("disabled");
  		document.querySelector('#new_student_pw').setAttribute("disabled", "disabled");
  		document.querySelector('#new_student_pw_submit').setAttribute("disabled", "disabled");
  		document.querySelector('#admit_student').removeAttribute("disabled");
  	}
  }
  
  function RequestStudents() {
  	socket.emit('Request_StudentsForClass', {
  		cid: getSelectedClassId()
  	});
  }
  
  function getSelectedStudentOption() {
  	return document.querySelector('#student_selector option:checked');
  }
  
  function handleReponseGetStudents(data) {
  	const student_selector = document.getElementById("student_selector");
  	student_selector.innerHTML = "";
  	data.enrollments.forEach(enrollment => {
  		const option = new Option(enrollment.student.username, enrollment.student._id);
  		if (enrollment.admitted === false) {
  			option.className = 'bg-info not-admitted ';
  		}
  		student_selector.add(option);
  	});
  }
  
  function RemoveStudent() {
  	socket.emit('Request_RemoveStudent', {
  		cid: getSelectedClassId(),
  		sid: getSelectedStudentOption().value
  	})
  }
  
  function AdmitStudent() {
  	socket.emit('Request_AdmitStudent', {
  		cid: getSelectedClassId(),
  		sid: getSelectedStudentOption().value
  	})
  }
  
  function changeStudentPassword() {
  	socket.emit('Request_ChangeStudentPassword', {
  		cid: getSelectedClassId(),
  		sid: getSelectedStudentOption().value,
  		password: document.querySelector('#new_student_pw').value
  	})
  }
  
  function handleResponseChangeStudentPassword(data) {
  	document.querySelector('#manage_students_alert_box').innerText = data.message;
  	document.querySelector('#manage_students_alert_box').style.display = "block";
  }
  
  function clearManageStudentsModal() {
  	document.querySelector('#manage_students_alert_box').innerText = '';
  	document.querySelector('#manage_students_alert_box').style.display = "none";
  }
  
  function initManageStudentsModule() {
  	document.querySelector('#student_selector').addEventListener('change', StudentSelectorChanged);
  	document.querySelector('#manage_students_button').addEventListener('click', RequestStudents);
  	document.querySelector('#remove_student').addEventListener('click', RemoveStudent);
  	document.querySelector('#admit_student').addEventListener('click', AdmitStudent);
  	document.querySelector('#new_student_pw_submit').addEventListener('click', changeStudentPassword);
  
  	$(".manage-students-modal").on("hidden.bs.modal", clearManageStudentsModal);
  
  	socket.on('Response_ChangeStudentPassword', handleResponseChangeStudentPassword);
  	socket.on('Response_AdmitStudent', 	RequestStudents);
  	socket.on('Response_RemoveStudent', RequestStudents);
  	socket.on('Response_StudentsForClass', handleReponseGetStudents);
  }
  
  window.addEventListener("load", initManageStudentsModule);
new_contents: function StudentSelectorChanged() {
  	document.querySelector('#remove_student').removeAttribute("disabled");
  	if (getSelectedStudentOption().className.indexOf('not-admitted') === -1) {
  		document.querySelector('#new_student_pw').removeAttribute("disabled");
  		document.querySelector('#new_student_pw_submit').removeAttribute("disabled");
  		document.querySelector('#admit_student').setAttribute("disabled", "disabled");
  	} else {
  		document.querySelector('#new_student_pw').setAttribute("disabled", "disabled");
  		document.querySelector('#new_student_pw_submit').setAttribute("disabled", "disabled");
  		document.querySelector('#admit_student').removeAttribute("disabled");
  	}
  }
  
  function RequestStudents() {
  	socket.emit('Request_StudentsForClass', {
  		cid: getSelectedClassId()
  	});
  }
  
  function getSelectedStudentOption() {
  	return document.querySelector('#student_selector option:checked');
  }
  
  function handleReponseGetStudents(data) {
  	const student_selector = document.getElementById("student_selector");
  	student_selector.innerHTML = "";
  	data.enrollments.forEach(enrollment => {
  		const option = new Option(enrollment.student.username, enrollment.student._id);
  		if (enrollment.admitted === false) {
  			option.className = 'bg-info not-admitted ';
  		}
  		student_selector.add(option);
  	});
  }
  
  function RemoveStudent() {
  	socket.emit('Request_RemoveStudent', {
  		cid: getSelectedClassId(),
  		sid: getSelectedStudentOption().value
  	})
  }
  
  function AdmitStudent() {
  	socket.emit('Request_AdmitStudent', {
  		cid: getSelectedClassId(),
  		sid: getSelectedStudentOption().value
  	})
  }
  
  function changeStudentPassword() {
  	socket.emit('Request_ChangeStudentPassword', {
  		cid: getSelectedClassId(),
  		sid: getSelectedStudentOption().value,
  		password: document.querySelector('#new_student_pw').value
  	})
  }
  
  function handleResponseChangeStudentPassword(data) {
  	document.querySelector('#manage_students_alert_box').innerText = data.message;
  	document.querySelector('#manage_students_alert_box').style.display = "block";
  }
  
  function clearManageStudentsModal() {
  	document.querySelector('#manage_students_alert_box').innerText = '';
  	document.querySelector('#manage_students_alert_box').style.display = "none";
  }
  
  function initManageStudentsModule() {
  	document.querySelector('#student_selector').addEventListener('change', StudentSelectorChanged);
  	document.querySelector('#manage_students_button').addEventListener('click', RequestStudents);
  	document.querySelector('#remove_student').addEventListener('click', RemoveStudent);
  	document.querySelector('#admit_student').addEventListener('click', AdmitStudent);
  	document.querySelector('#new_student_pw_submit').addEventListener('click', changeStudentPassword);
  
  	$(".manage-students-modal").on("hidden.bs.modal", clearManageStudentsModal);
  
  	socket.on('Response_ChangeStudentPassword', handleResponseChangeStudentPassword);
  	socket.on('Response_AdmitStudent', 	RequestStudents);
  	socket.on('Response_RemoveStudent', RequestStudents);
  	socket.on('Response_StudentsForClass', handleReponseGetStudents);
  }
  
  window.addEventListener("load", initManageStudentsModule);
subject: Refactor student selector changed