var imageprefix 
if (  htmls[htmls.length-1].indexOf('.') > 2 ) imageprefix = htmls[htmls.length-1].substring(0,3)
else imageprefix = htmls[htmls.length-1].substring(0,2)
//alert(htmls[htmls.length-1].indexOf('.')+imageprefix);
document.getElementById("autoh3").style.backgroundImage = 'url(images/h3-'+imageprefix+'.png)';