function changeImage(the_source){
    
	if (the_source =='rysunek1'){
		document.main.src = document.rysunek1.src;
	}
	else if (the_source =='rysunek2'){
		document.main.src = document.rysunek2.src;
	}
	else 	if (the_source =='rysunek3'){
		document.main.src = document.rysunek3.src;
	}
}