// JavaScript Document
var page_final = 20;
var string_query = window.location.search;//?1&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x
string_query = string_query.split('?');
string_query = string_query[1];//1&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x&x
var array_query = string_query.split('&');//[1][x][x][x]...
var quiz_page = parseInt(array_query[0]);//[1]
var next_page = quiz_page + 1;

function checkForm(answer) {
	if(!answer || answer == "") {
		alert("Please select an answer.");
		return false;
	}else{
		var new_string_query = "?" + next_page;
		var string_answer;
		var next_url;
		for(i=1;i<array_query.length;i++) {
			if(i==quiz_page) {
				string_answer = "&" + answer;
			}else{
				string_answer = "&" + array_query[i];
			}
			new_string_query += string_answer;
		}
		if(quiz_page == page_final) {
			//window.location = "results.html" + new_string_query;
			next_url = "results.html" + new_string_query;
		} else {//
			//window.location = "page"+next_page+".html" + new_string_query;
			next_url = "page"+next_page+".html" + new_string_query;
		}
		document.getElementById('next_link').href = next_url;
		return true;
	}
}