browser_version= parseInt(navigator.appVersion);
browser_type = navigator.appName;

function setCookie(name, value, expire) {
   document.cookie = name + "=" + escape(value)   + ((expire == null) ? "" : ("; expires=" + expire.toGMTString()))
}

function getCookie(Name) {
   var search = Name + "="
   if (document.cookie.length > 0) { // if there are any cookies
   	 offset = document.cookie.indexOf(search)
	 if (offset != -1) { // if cookie exists
	    offset += search.length
		// set index of beginning of value
		end = document.cookie.indexOf(";", offset)
		// set index of end of cookie value
		if (end == -1)             
		  end = document.cookie.length         
		return unescape(document.cookie.substring(offset, end))
     }
}}

function onClick_checkbox(obj){
	var i, elem;
	if (!obj.checked)
		return true;
	for (i = 0; i < document.form1.elements.length; i++) {
		elem = document.form1.elements[i];
		if ((elem.type == "checkbox") && (elem.name != obj.name) )
			elem.checked = false;
	}
}

function find_checkbox(){
	var i, elem, answer = "x";
	for (i = 0; i < document.form1.elements.length; i++) {
		elem = document.form1.elements[i];
		if ((elem.type == "checkbox") && (elem.checked) )
			answer = elem.name;
	}
	return answer;
}

function onClick_OK(form){
	correct = new Array("b","a","b","b","b","b","c","b","d")
	var question = "Q"+nr
	var address = window.location.href, poz;
	var your_answer = find_checkbox()

	if (your_answer == "x") {
		poz = address.indexOf("opt=")
		if (poz != -1) {
			address = address.substr(0,poz-1);
			window.location.href = address;
			if (browser_type == 'Microsoft Internet Explorer')
				window.location.reload(true);
		}
		return false;
	}
	if (answer == "?") {
		setCookie(question, your_answer)
		if (your_answer == correct[nr-1]) {
			score++;
			setCookie("score", score);
			form.score.value = score;
		}
	}
	
	poz = address.indexOf("opt=")
	if (poz != -1) {
		address = address.substr(0,poz-1);
	} else {
		poz = address.indexOf("#");
		if (poz != -1) 
			address = address.substr(0,poz-1);
	}
	address+= "?opt="+your_answer+"#response";
	window.location.href = address;
	return true;
}