function selectTab(id)
{
   var element;

   var type = '';
   if (id.indexOf('actie') != -1)
      type = '_actie';
   if (id.indexOf('groen') != -1)
      type = '_groen';
      
   element = document.getElementById('tab_top5_combinatie' + type);
   if (element != null) element.className = 'tab';
   element = document.getElementById('tab_top5_stroom_enkel'  + type);
   if (element != null) element.className = 'tab';
   element = document.getElementById('tab_top5_stroom_dubbel' + type);
   if (element != null) element.className = 'tab';
   element = document.getElementById('tab_top5_gas'  + type);
   if (element != null) element.className = 'tab';
   element = document.getElementById('tab_top5_zakelijk'  + type);
   if (element != null) element.className = 'tab';

   element = document.getElementById('tab_top5_' + id);
   if (element != null) element.className = 'tab_active';
   
   element = document.getElementById('tabblad_top5_combinatie' + type);
   if (element != null) 
      element.className = 'tabblad_top5_invisible';
   element = document.getElementById('tabblad_top5_stroom_enkel' + type);
   if (element != null) element.className = 'tabblad_top5_invisible';
   element = document.getElementById('tabblad_top5_stroom_dubbel' + type);
   if (element != null) element.className = 'tabblad_top5_invisible';
   element = document.getElementById('tabblad_top5_gas' + type);
   if (element != null) element.className = 'tabblad_top5_invisible';
   element = document.getElementById('tabblad_top5_zakelijk' + type);
   if (element != null) element.className = 'tabblad_top5_invisible';

   element = document.getElementById('tabblad_top5_' + id);
   if (element != null) element.className = 'tabblad_top5_visible';
}

function higlightTab(id)
{
   var element;

   element = document.getElementById('tab_top5_' + id);
   var className = element.className;
   if (className == "tab")
      element.className = "tab_hover";
   if (className == "tab_active")
      element.className = "tab_active_hover";
}

function dehiglightTab(id)
{
   var element;

   element = document.getElementById('tab_top5_' + id);

   var className = element.className;
   if (className == "tab_hover")
      element.className = "tab";
   if (className == "tab_active_hover")
      element.className = "tab_active";
}