function showTab(obj)
{
  desc_cont = document.getElementById('pi-tabs-desc-cont');
  desc_cont.style.display = 'none';
  document.getElementById('pi-tabs-desc').className = 'pi-li-inactive';
  
  if(document.getElementById('pi-tabs-comp')){
    comp_cont = document.getElementById('pi-tabs-comp-cont');
    comp_cont.style.display = 'none';
    document.getElementById('pi-tabs-comp').className = 'pi-li-inactive';
  }
  
  if(document.getElementById('pi-tabs-use')){
    use_cont = document.getElementById('pi-tabs-use-cont');
    use_cont.style.display = 'none';
    document.getElementById('pi-tabs-use').className = 'pi-li-inactive';
  }
  
  if(document.getElementById('pi-tabs-ingrid')){
    ingrid_cont = document.getElementById('pi-tabs-ingrid-cont');
    ingrid_cont.style.display = 'none';
    document.getElementById('pi-tabs-ingrid').className = 'pi-li-inactive';
  }
  
  obj.className = 'pi-li-active';
  document.getElementById(obj.id + '-cont').style.display = 'block';
}