var num = 1;
var loca = "../img/ref/02_ref2/";
var t = "<section>";
var k = "</section>";
var tmp = "";

for(var i = 1; i < 39; i++){
tmp += t + ("<img src="+ loca + num + ".png>") + k;
num++;
console.log(tmp);
document.write(tmp);
tmp = "";
}