/* This code dynamically fills the topic and subject dropdown lists
   for a specified form (upload content / edit content pages) */

// this function is used to fill the topic list on load
function fillTopics(current_form) {
	form = document.getElementById(current_form);
	addOption(form.topic, "Math", "Math", "");
	addOption(form.topic, "Science", "Science", "");
	addOption(form.topic, "English", "English", "");
	addOption(form.topic, "Economics", "Economics", "");
	addOption(form.topic, "Engineering", "Engineering", "");
}

// on selection of topic this function will activate
function selectSubject(the_form) {
	form = document.getElementById(the_form);
	removeAllOptions(form.subject);
	addOption(form.subject, "", "Select Subject", "");

	if (form.topic.value == 'Math') {
		addOption(form.subject, "Pre-Algebra", "Pre-Algebra");
		addOption(form.subject, "Algebra 1", "Algebra 1");
		addOption(form.subject, "Algebra 2", "Algebra 2");
		addOption(form.subject, "Geometry", "Geometry");
		addOption(form.subject, "Trigonometry", "Trigonometry");
		addOption(form.subject, "Precalculus", "Precalculus");
		addOption(form.subject, "AP Calculus", "AP Calculus");
		addOption(form.subject, "AP Statistics", "AP Statistics");
		addOption(form.subject, "Differential Equations", "Differential Equations");
	}
	else if (form.topic.value == 'Science') {
		addOption(form.subject, "Astronomy", "Astronomy");
		addOption(form.subject, "Earth Science", "Earth Science");
		addOption(form.subject, "AP Biology ", "AP Biology ");
		addOption(form.subject, "AP Chemistry", "AP Chemistry");
		addOption(form.subject, "AP Physics B", "AP Physics B");
		addOption(form.subject, "AP Physics C", "AP Physics C");
		addOption(form.subject, "AP Environmental Science", "AP Environmental Science", "");
	}
	else if (form.topic.value == 'English') {
		addOption(form.subject, "Composition", "Composition");
		addOption(form.subject, "Reading", "Reading");
		addOption(form.subject, "Creative Writing", "Creative Writing");
		addOption(form.subject, "American Literature", "American Literature");
		addOption(form.subject, "World Literature", "World Literature");
		addOption(form.subject, "Theatre as Literature", "Theatre as Literature");
		addOption(form.subject, "AP English Language and Composition", "AP English Language and Composition");
		addOption(form.subject, "AP English Literature and Composition", "AP English Literature and Composition");
	}
	else if (form.topic.value == 'Economics') {
		addOption(form.subject, "AP Macroeconomics", "AP Macroeconomics");
		addOption(form.subject, "AP Microeconomics", "AP Microeconomics");
	}
	else if (form.topic.value == 'Engineering') {
		addOption(form.subject, "Electrical", "Electrical");
		addOption(form.subject, "Mechanical,", "Mechanical");
		addOption(form.subject, "Physics,", "Physics");
		addOption(form.subject, "Civil,", "Civil");
		addOption(form.subject, "Computer,", "Computer");
		addOption(form.subject, "Software,", "Software");
		addOption(form.subject, "Aerospace,", "Aerospace");
		addOption(form.subject, "Chemical,", "Chemical");
		addOption(form.subject, "Biomedical,", "Biomedical");
		addOption(form.subject, "Materials,", "Materials");
		
	}
}

function removeAllOptions(selectbox)
{
	var i;
	for (i=selectbox.options.length-1; i >= 0; i--)
	{
		//selectbox.options.remove(i);
		selectbox.remove(i);
	}
}

function addOption(selectbox, value, text)
{
	var optn = document.createElement("OPTION");
	optn.text = text;
	optn.value = value;

	selectbox.options.add(optn);
}