var cnt = 40;
var random = Math.random();
var picnum = Math.round(random*cnt)+1;
var pan = "bangkok/pan/pan"+picnum+".jpg";
var img = '<img id="panpic" src="'+pan+'" alt="Elegant riverside holiday apartments for rent in Bangkok - Baan Sathorn Chaophraya" title="Elegant riverside holiday apartments for rent in Bangkok - Baan Sathorn Chaophraya" width="437" height="150" />'