function previewHoriz(page) {
OpenWin = this.open(page, "CtrlWindow", "width=1070,height=720,status=no,address=no,toolbar=no,menubar=no,location=no,resizable=yes");
}

function previewVert(page) {
OpenWin = this.open(page, "CtrlWindow", "width=740,height=1070,status=no,address=no,toolbar=no,menubar=no,location=no,scrollbars=yes,resizable=yes");
}

function previewVideo(page) {
OpenWin = this.open(page, "CtrlWindow", "width=720,height=420,status=no,address=no,toolbar=no,menubar=no,location=no,scrollbars=no,resizable=yes");
}

function showOverlay(id, img) {
  div=document.getElementById(id);

  if ( img ) {
    x=(img.width / 2) - 130; 
    y=(img.height / 2) - 22; 
    div.style.top=y+"px";
    div.style.left=x+"px";
}

  div.style.visibility="visible";
}

function hideOverlay(id) {
  div=document.getElementById(id);
  div.style.visibility="hidden";
}