function change_visibility (num) {
  qdivs = new Array();
  var k = 0;
  for (var i=1; i<=100; i++)
  {
    qdivs[i] = "q" + i;    
  }
document.getElementById(qdivs[parseFloat(num)]).style.display="none";
document.getElementById(qdivs[parseFloat(num)+1]).style.display="block";
}

function change_visibility2(nam, num) {
  qdivs = new Array();
  for (var i=0; i<=100; i++)
  {
    qdivs[i] = nam +  i;
  }
document.getElementById(qdivs[parseFloat(num)]).style.display="none";
document.getElementById(qdivs[parseFloat(num)+1]).style.display="block";
}

function change_visibility3(nam, num) {
  qdivs = new Array();
  for (var i=1; i<=num+1; i++)
  {
    qdivs[i] = nam +  i;
    document.getElementById(qdivs[i]).style.display="none";
  }
document.getElementById(qdivs[parseFloat(num)+1]).style.display="block";
}


function settime(timed, tform, tmax) {
	time_diff=timed;
	max=tmax;
	formn=tform;
	change_visibility2(formn , 0);
	countDown();
}

function countDown() {
           work_number = time_diff--;
	   if (time_diff<0) {change_visibility3(formn , max);
           document.getElementById('counter').innerHTML = "Время вышло!";}
	   else {
           	days = Math.floor(work_number / 86400);      
	           work_number -= days * 86400;
	           hours = Math.floor(work_number / 3600);
	           work_number -= hours * 3600;
	           minutes = Math.floor(work_number / 60);
	           work_number -= minutes * 60;
	           seconds = Math.floor(work_number % 60);
	           hours = (hours < 10) ? "0"+hours : hours;
	           minutes = (minutes < 10) ? "0"+minutes : minutes;
	           seconds = (seconds < 10) ? "0"+seconds : seconds;
	           values = [
	              declOfNum(hours, ["час", "часа", "часов"]), 
	              declOfNum(minutes, ["минута", "минуты", "минут"]), 
	              declOfNum(seconds, ["секунда", "секунды", "секунд"])
	           ];
	           document.getElementById('counter').innerHTML =  "Осталось: " + values.join(" ") + ".";      
	    }
        }

function declOfNum(number, titles) {
     cases = [2, 0, 1, 1, 1, 2];
     return "<b>" + number + "</b> " + titles[ (number%100>4 && number%100<20)? 2 : cases[Math.min(number%10, 5)] ];
}