function Change_Img(picIndex) {
		
	if(actElementID == picIndex) {
		actElementID = 0;		
	}
	
	for(var i=0; i < picIndex; i++) {	
		var id = 'picgalimg'+i;
		if(i == actElementID) {
			document.getElementById(id).style.display = "block"; 	
		}
		else {
			document.getElementById(id).style.display = "none"; 
		}
	}
	
	actElementID++;
}