var current_tab = 'description';

function change_tab(id) {
	
	var old_tab = document.getElementById(current_tab);
	var new_tab = document.getElementById(id);

	if (old_tab.id == 'description') {
		old_tab.className = 'unselected_left';
	} else {
		old_tab.className = 'unselected';
	}

	if (new_tab.id == 'description') {
		new_tab.className = 'selected_left';
	} else {
		new_tab.className = 'selected';
	}
		

	var old_content = document.getElementById(current_tab + '_content');
	var new_content = document.getElementById(id + '_content');
	
	old_content.style.display = 'none';
	new_content.style.display = 'block';

	current_tab = id;

} 

function changeColorIn(element) {
	element.style.backgroundColor = '#CCCCCC';
}

function changeColorOut(element) {
	element.style.backgroundColor = '#FFFFFF';
}