var TABoverviewOBJ    = document.getElementById('tab_overview');
var TABdetailsOBJ     = document.getElementById('tab_details');
var TABreviewsOBJ     = document.getElementById('tab_reviews');
var TABingredientsOBJ = document.getElementById('tab_ingredients');
var TABvideoOBJ       = document.getElementById('tab_videos');

TABingredientsOBJ.style.display = 'none';
TABvideoOBJ.style.display       = 'none';

var prevLink;
var prevTab;

if(TABoverviewOBJ.innerHTML.length > 1)
{
  var prevLink = document.getElementById('link_overview');
  var prevTab  = TABoverviewOBJ;
  TABdetailsOBJ.style.display = 'none';
  TABreviewsOBJ.style.display = 'none';
}

else if (TABdetailsOBJ.innerHTML.length > 1)
{
  var prevLink = document.getElementById('link_details');
  var prevTab  = TABdetailsOBJ;
  TABoverviewOBJ.style.display = 'none';
  TABreviewsOBJ.style.display = 'none';
}

else 
{
  var prevLink = document.getElementById('link_reviews');
  var prevTab  = TABreviewsOBJ;
  TABoverviewOBJ.style.display = 'none';
  TABdetailsOBJ.style.display = 'none';
}