function open_page(div_num)
{
var divs='#cont'+div_num;
var buts='but'+div_num;

document.getElementById('but1').className='but';
document.getElementById('but2').className='but';
document.getElementById('but3').className='but';
document.getElementById('but4').className='but';

if (div_num!=5) document.getElementById(buts).className='on_but';

if (document.getElementById('cont1').style.display=='block') $('#cont1').hide('slow');
if (document.getElementById('cont2').style.display=='block') $('#cont2').hide('slow');
if (document.getElementById('cont3').style.display=='block') $('#cont3').hide('slow');
if (document.getElementById('cont4').style.display=='block') $('#cont4').hide('slow');
if (document.getElementById('cont5').style.display=='block') $('#cont5').hide('slow');


$(divs).slideDown('slow');
}


function reg_hint(num_pole)
{
var pole='#hint_'+num_pole;

document.getElementById('reg_1').className='in_reg';
document.getElementById('reg_2').className='in_reg';
document.getElementById('reg_3').className='in_reg';

document.getElementById('reg_'+num_pole).className='in_reg_focus';

$('#hint_1').fadeOut('slow');
$('#hint_2').fadeOut('slow');
$('#hint_3').fadeOut('slow');

$(pole).fadeIn('slow');
}