static S hcenterimage(S imgURL) {
  ret hcenterimage(imgURL, null, "", "");
}

static S hcenterimage(S imgURL, O[] imgParams, S beforeContents, S afterContents) {
  ret
    "<table width='100%' height='100%' border=0><tr><td align=center>" + beforeContents + tag("img", "", concatArrays(new O[] {"src", imgURL}, imgParams)) + afterContents + "</td></tr></table>\n";
}