//wykamath.com javascript
window.onload = init;

function init(){
	var v = getElementsByClassName(document.getElementById("mainContent"), "collapsible")
	for(var i=0; i<v.length; i++)
		makeCollapsible(v[i]);
}

function getElementsByClassName(node, classname)
{
    var a = [];
    var re = new RegExp('\\b' + classname + '\\b');
    var els = node.getElementsByTagName("*");
    for(var i=0,j=els.length; i<j; i++)
        if(re.test(els[i].className))a.push(els[i]);
    return a;
}

function toggleDisplay(node){
	if(node.style.display == 'none')
		node.style.display = 'inline';	
	else
		node.style.display = 'none';
}

function toggleShowHide(node) {
	if(node.innerHTML == "Show Answer")
		node.innerHTML = "Hide";
	else
		node.innerHTML = "Show Answer";
}

function toggleAll() {
	toggleShowHide(this);
	toggleDisplay(this.previousSibling);
}

function addShowHide(node){
	node.firstChild.style.display = "none";
	var link = document.createElement("a");
	//link.href = "#";
	link.onclick = toggleAll;
	link.innerHTML = "Show Answer";
	node.appendChild(link);
}

function makeCollapsible(node){
	toggleDisplay(node.firstChild);
	addShowHide(node);
}