function slidePRight() {
 if ((myPActTnNo + myPTnDispNo) < myNoPImg) {
  myPActTnNo += 1;
  dispPSlide();
 }
}

function slidePLeft() {
 if (myPActTnNo > 0) {
  myPActTnNo -= 1;
  dispPSlide();
 }
}

function dispPSlide() {
 if (myPActTnNo == 0) {
   document.getElementById('p_nav_l').innerHTML = '<img src="/images/galnavleftdisabled.png">'
  } else {
   document.getElementById('p_nav_l').innerHTML = '<a href="javascript: slidePLeft();"><img src="/images/galnavleft.png"></a>'
 }
 for (var i = myPActTnNo; i < myNoPImg && (i - myPActTnNo) < myPTnDispNo; i++) {
  document.getElementById('p' + (i - myPActTnNo)).innerHTML = '<a href="javascript: showPImg(' + i + ');"><img src="/images/gallery/' + myPTnImg[i] + '"></a>'
 }
 if (myPActTnNo < (myNoPImg - myPTnDispNo)) {
   document.getElementById('p_nav_r').innerHTML = '<a href="javascript: slidePRight();"><img src="/images/galnavright.png"></a>'
  } else {
   document.getElementById('p_nav_r').innerHTML = '<img src="/images/galnavrightdisabled.png">'
 }
}

function showPImg(inNo) {
 document.getElementById('largeImg').innerHTML = '<img class="gal_largeimg" src="/images/gallery/' + myPImg[inNo] + '">'
}

function slideARight() {
 if ((myAActTnNo + myATnDispNo) < myNoAImg) {
  myAActTnNo += 1;
  dispASlide();
 }
}

function slideALeft() {
 if (myAActTnNo > 0) {
  myAActTnNo -= 1;
  dispASlide();
 }
}

function dispASlide() {
 if (myAActTnNo == 0) {
   document.getElementById('a_nav_l').innerHTML = '<img src="/images/galnavleftdisabled.png">'
  } else {
   document.getElementById('a_nav_l').innerHTML = '<a href="javascript: slideALeft();"><img src="/images/galnavleft.png"></a>'
 }
 for (var i = myAActTnNo; i < myNoAImg && (i - myAActTnNo) < myATnDispNo; i++) {
  document.getElementById('a' + (i - myAActTnNo)).innerHTML = '<a href="javascript: showAImg(' + i + ');"><img src="/images/gallery/' + myATnImg[i] + '"></a>'
 }
 if (myAActTnNo < (myNoAImg - myATnDispNo)) {
   document.getElementById('a_nav_r').innerHTML = '<a href="javascript: slideARight();"><img src="/images/galnavright.png"></a>'
  } else {
   document.getElementById('a_nav_r').innerHTML = '<img src="/images/galnavrightdisabled.png">'
 }
}

function showAImg(inNo) {
 document.getElementById('largeImg').innerHTML = '<img class="gal_largeimg" src="/images/gallery/' + myAImg[inNo] + '">'
}