// random number
var Q = 44;
var rannum=Math.round(Math.random()*(Q-1));

if (rannum < 10) rannum = Q+10;
  if (rannum = 16) rannum = 17;
var a = "http://www.macphailwoods.org/blog/files/images/grntmb-0";
var b = ".thumbnail.jpg";

function showpic() {document.write('<img src="'+a+rannum+b+'">');}
showpic();