function insertSmile(code){
  clearField(getObj('textarea'), 'text příspěvku');
  getObj('textarea').value += " " + code + " ";
}

function clearField(obj, str){
  if(obj.value == str) obj.value='';
}

function validateComment(obj){
  if(obj.captcha.value == ''
     || obj.captcha.value == 'opište číslo z obrázku' 
     || obj.author.value == '' 
     || obj.cont.value == '' 
     || obj.cont.value == 'text příspěvku' 
     || (obj.email.value != '' && wrong_mail_address(obj.email.value))
     ){
    obj.submit_comment.disabled=true;
  }
  else{
    obj.submit_comment.disabled=false;
  }
}


function wrong_mail_address(adresa){
  var re = /^[_a-zA-Z0-9\.\-]+@[_a-zA-Z0-9\.\-]+\.[a-zA-Z]{2,4}$/;
  return re.test(adresa) == 0;
}

function getObj(id){
   if(Boolean(document.getElementById))
      return document.getElementById(id);
   else if(Boolean(document.all))
      return eval('document.all.'+id);
   else
      return eval('document.'+id);
}


function clearkeywords(){
  x=getObj('search');
  if(x.keywords.value=='Zadejte klíčová slova...') x.keywords.value='';
}

//-----------------------------------------------------------------------------
// kontrola dostatecneho vyplneni formulare (inputy oznacene rel="required")

function validateNews(form){
  if(form.email.value == '' || form.email.value == 'Vložte Váš email...')
    form.register_newsletter.disabled=true;
  else
    form.register_newsletter.disabled=false;
}