function expand_me(did, knop) {
  if ( knop == 'on') {
    document.getElementById(did+'_expanded').style.display = 'none'
    document.getElementById(did+'_collapsed').style.display = 'block'
  }
  if ( knop == 'off') {
    document.getElementById(did+'_expanded').style.display = 'block'
    document.getElementById(did+'_collapsed').style.display = 'none'
  }
}