// finish preloading thumbnails

for ( nth = 4; nth < maxthm; nth++ ) {
    thms[nth].src = thmdir + "/"+thmnams[nth]+".jpg";
}

// finish preloading big images, maybe only one loaded so far

for ( nth = 1; nth < maxthm; nth++ ) {
    if ( !pix[nth].src ) { // in case already loaded

        pix[nth].src = imgdir + "/"+picnams[nth]+".jpg";
    }
}