var middleHeight = 0;

function setMiddleHeights() {
  middleHeight = document.body.offsetHeight - 255;

  a = document.getElementById('page_blank');
  b = document.getElementById('page_contact');
  c = document.getElementById('page_about');
  d = document.getElementById('page_driftwood');
  e = document.getElementById('page_media');

  a.style.height = middleHeight;
  b.style.height = middleHeight;
  c.style.height = middleHeight;
  d.style.height = middleHeight;
  e.style.height = middleHeight;

  a = null;
  b = null;
  c = null;
  d = null;
  e = null;
}

function showPage(pg,pic) {
  a  = document.getElementById('page_blank');
  b  = document.getElementById('page_contact');
  bb  = document.getElementById('pic_contact');
  c  = document.getElementById('page_about');
  cc  = document.getElementById('pic_about');
  d  = document.getElementById('page_driftwood');
  dd  = document.getElementById('pic_driftwood');
  e  = document.getElementById('page_media');
  ee  = document.getElementById('pic_media');

  a.style.display = 'none';
  b.style.display = 'none';
  bb.className = 'opaque_100';
  c.style.display = 'none';
  cc.className = 'opaque_100';
  d.style.display = 'none';
  dd.className = 'opaque_100';
  e.style.display = 'none';
  ee.className = 'opaque_100';

  if(pg) {
    document.getElementById(pic).className = 'opaque_050';
    document.getElementById(pg).style.display = 'block';
  } else {
    a.style.display = 'block';
  }

  a  = null;
  b  = null;
  bb = null;
  c  = null;
  cc = null;
  d  = null;
  dd = null;
  e  = null;
  ee = null;
}

function checkContactForm() {
  a = document.getElementById('toaddress').value;
  b = document.getElementById('fromaddress').value;
  c = document.getElementById('subjectline').value;
  d = document.getElementById('bodypart').value;

  if(a && b && c && d) {
    document.getElementById('emailform').submit();
  } else {
    alert('Please fill out the form completely.');
  }

  a = null;
  b = null;
  c = null;
  d = null;
}