// Add a class to an element, appending to existing
// classes where they exist

function addClass(element,value) {
    if (!element.className) {
        element.className = value;
    } else {
        newClassName = element.className;
        newClassName+= " ";
        newClassName+= value;
        element.className = newClassName;
    }
}

 
// Verify the existence of a class name on an element

function hasClass(obj,cName) { 
 return new RegExp('\\b'+cName+'\\b').test(obj.className);
}

// Remove classes from an element

function removeClass(obj,cName) {
 if (!hasClass(obj,cName)) return false; 
 var rep=obj.className.match(' '+cName)?' '+cName:cName; 
 obj.className=obj.className.replace(rep,''); 
 return true; 
}


// Add functions to the page onLoad event

function addLoadEvent(func){
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      oldonload();
      func();
    }
  }
}

addLoadEvent(setQEvents);

function getRef(id){var elem = document.getElementById(id);return elem;}

function addEvent(elm, evType, fn, useCapture) {    
 if (elm.addEventListener) {        
  elm.addEventListener(evType, fn, useCapture);        
  return true;   
 } else if (elm.attachEvent) {
  var r = elm.attachEvent("on"+evType, fn);
   return r;
 } else {
 }
}

function setQEvents(){
		var yes11 = getRef("Radio15");
		var no11 = getRef("Radio16");
		var yes14 = getRef("chbQ14a");
		var no14 = getRef("chbQ14b");
		var yes15 = getRef("chbQ15a");
		var no15 = getRef("chbQ15b");
		var yes17 = getRef("chbQ17a");
		var no17 = getRef("chbQ17b");

		addEvent(yes11,"click",checkyes11,"false");
		addEvent(no11,"click",checkno11,"false");
		addEvent(yes14,"click",checkyes14,"false");
		addEvent(no14,"click",checkno14,"false");
		addEvent(yes15,"click",checkyes15,"false");
		addEvent(no15,"click",checkno15,"false");
		addEvent(yes17,"click",checkyes17,"false");
		addEvent(no17,"click",checkno17,"false");
}

function checkyes11 (){	removeClass(document.body,"q11no"); addClass(document.body,"q11yes"); }
function checkno11 (){ removeClass(document.body,"q11yes"); addClass(document.body,"q11no"); }

function checkyes14 (){
	removeClass(getRef("q14_a"),"hide");
	removeClass(getRef("q14_b"),"hide");
	addClass(getRef("q14_a"),"show");
	addClass(getRef("q14_b"),"show");
}

function checkno14 (){
	removeClass(getRef("q14_a"),"show");
	removeClass(getRef("q14_b"),"show");
	addClass(getRef("q14_a"),"hide");
	addClass(getRef("q14_b"),"hide");
}

function checkyes15 (){
	removeClass(getRef("q15_a"),"hide");
	removeClass(getRef("q15_b"),"hide");
	addClass(getRef("q15_a"),"show");
	addClass(getRef("q15_b"),"show");
}

function checkno15 (){
	removeClass(getRef("q15_a"),"show");
	removeClass(getRef("q15_b"),"show");
	addClass(getRef("q15_a"),"hide");
	addClass(getRef("q15_b"),"hide");
}

function checkyes17 (){
	removeClass(getRef("q17_a"),"hide");
	removeClass(getRef("q17_b"),"hide");
	addClass(getRef("q17_a"),"show");
	addClass(getRef("q17_b"),"show");
}

function checkno17 (){
	removeClass(getRef("q17_a"),"show");
	removeClass(getRef("q17_b"),"show");
	addClass(getRef("q17_a"),"hide");
	addClass(getRef("q17_b"),"hide");
}