var curr_seld = {a:1,b:1,c:1,d:1};//default value;

function $(sID) {return document.getElementById(sID);}

function change_img(xIn) {
	x = xIn.substring(0,1);//don't ask :-S
	i = xIn.substring(1,2);
	$('img'+x).src = $('img'+x+i).src;
	$(x+curr_seld[x]).className = "";
	curr_seld[x] = i;
	$(x+curr_seld[x]).className = "selected"+x;
}