function testNavPrev(div, select) {
  var prevUrl = getMangaMirror($("#mirrorList").val()).previousChapterUrl(select, $(div), $("#lstChaps").val());
  if (prevUrl === null || prevUrl === undefined || prevUrl.trim().length === 0) {
    modifyResult("testnavprev", $("<span>Previous URL is empty, the current chapter must be the first chapter published. If not, check your code.</span>"));
    modifyComment("testnavprev", "Verify that the selected chapter is the first published.");