function show_random_photo()
{
	var project_number = 1 + Math.floor(Math.random() * 4);

	var range_a = 1;
	var range_b;
	var project_name;

	switch(project_number)
	{
		case 1:
			range_b = 23;
			project_name = 'ep';
			break;
		case 2:
			range_b = 20;
			project_name = 'wbhq';
			break;
		case 3:
			range_b = 12;
			project_name = 'kt';
			break;
		case 4:
			range_b = 19;
			project_name = 'kzo';
			break;
	}

	var photo_number = range_a + Math.floor(Math.random() * (range_b - range_a + 1));

	if (photo_number < 10)
	{
		photo_number = '0' + photo_number;
	}

	document.write('<img id="projekty_photo" src="gfx/projects/'+project_name+photo_number+'.jpg" alt="zdjêcie" />');
}