var i       = 0;
var img_old = 1;
var j       = 10;

function rotate_img() {

   while( i == 0 || i >= images.length || i == img_old ) {
      i = parseInt( Math.random() * j );
   } // End while
   
   img_old     = i;
   img_obj.src = images[ 0 ] + images[ i ];
   
   setTimeout( "rotate_img()", 8000 );

} // End function rotate_img