function verander_tab(tabname) {
 for(tabnr=1;tabnr<=11;tabnr++) {
  if (document.getElementById('tab' + tabnr)) {
   var tabdown = document.getElementById('tab' + tabnr);
   tabdown.className = "";
   var tabdown = document.getElementById('htmltab' + tabnr);
   tabdown.className = "tabnotselected";
  }
 }
 var tabup = document.getElementById(tabname);
 tabup.className = "selected";
 var tabup = document.getElementById('html' + tabname);
 tabup.className = "tabselected";
}
function hightlight(naam) {
 naam.style.backgroundColor='#AAFFCC';
 naam.style.cursor='pointer';
}
function dehightlight(naam,kleur) {
 naam.style.backgroundColor='#'+kleur;
 naam.style.cursor='auto';
}