var w=316;
if (sn==2)
	 w=391;
if (sn==3)
	 w=448;
if (sn==4)
	 w=530;
var h=w*347/791;
var lw=' width="'+w+'"';
var lh=' height="'+h+'"';
var la=' alt="School book example"';
var lt=' title="School book example"';
var b=' border="0"';
document.write('<img src="../images/Schoolbooks.jpg"'+lw+lh+la+lt+b+'>');