function MaxTextboxChars(pocet,t)
{ 
  if(t.value.length>pocet) t.value = t.value.substr(0,pocet);
}

function MaxTextboxCharsWithDisplay(pocet,t, idCharsWritten, idCharsLeft)
{ 
  if(t.value.length > pocet) t.value = t.value.substr(0,pocet);  
  idCharsWritten.innerHTML = t.value.length;
  idCharsLeft.innerHTML = pocet - t.value.length;
}