function isEmpty(string){
	return ((string == null) || (string.length == 0));
}

//TODO: udelat poradnou kontrolu URI
function isUrl(theString){
/*alert(theString);
var splitted = theString.match("(http:\/\/[_a-zA-Z0-9\.\-]+\.[a-zA-Z]{2,4}\/{1}[-_~&=\?\.a-z0-9\/]*)");
    return (splitted == null) ? false : true;*/
	 return (theString != "http://");
}

function addSmajl(theSmajl){
  var message = document.getElementById('message');
  
  message.value = message.value + '[s]' + theSmajl + '[/s]';
}