var setActive = function(element_o)
{
	if(element_o)
	{

		var current_de = document.getElementById(element_o);
			current_de.className = 'active';

			var link_a = current_de.getElementsByTagName('a');
			if (link_a)
			{
    			link_a[0].className = 'active';
    		}

    		var div_a = current_de.getElementsByTagName('div');

			if (div_a)
			{
    			div_a[0].className = 'active';
    		}
	}
};

function setDisplay(element_o)
{
	document.getElementById(element_o).style.display = document.getElementById(element_o).style.display ? '' : 'none';
}

function setImageSwith(element_o, from_s, to_s)
{
	if(element_o)
	{
    	img_a = element_o.getElementsByTagName('img');

		if (typeof img_a[0] != 'undefined')
    		img_a[0].src = img_a[0].src.replace(from_s, to_s);
    }
};

function setWriterOnChange(select_o)
{
	document.getElementById('writer_1').style.display = 'none';
	document.getElementById('writer_2').style.display = 'none';
	document.getElementById('writer_3').style.display = 'none';
	document.getElementById('writer_4').style.display = 'none';
	
	var value_u = select_o.options[select_o.selectedIndex].value;

	if (value_u == '1')
	{
		document.getElementById('writer_1_spacer').style.display = '';
		document.getElementById('writer_1').style.display = '';
	}

	if (value_u == '2')
	{	
		document.getElementById('writer_1_spacer').style.display = '';
		document.getElementById('writer_2_spacer').style.display = '';
		document.getElementById('writer_1').style.display = '';
		document.getElementById('writer_2').style.display = '';
	}
	
	if (value_u == '3')
	{
		document.getElementById('writer_1_spacer').style.display = '';
		document.getElementById('writer_2_spacer').style.display = '';
		document.getElementById('writer_3_spacer').style.display = '';
		document.getElementById('writer_1').style.display = '';
		document.getElementById('writer_2').style.display = '';
		document.getElementById('writer_3').style.display = '';
	}
	
	if (value_u == '4')
	{
		document.getElementById('writer_1_spacer').style.display = '';
		document.getElementById('writer_2_spacer').style.display = '';
		document.getElementById('writer_3_spacer').style.display = '';
		document.getElementById('writer_4_spacer').style.display = '';
		document.getElementById('writer_1').style.display = '';
		document.getElementById('writer_2').style.display = '';
		document.getElementById('writer_3').style.display = '';
		document.getElementById('writer_4').style.display = '';
	}
	
}