function popup(url, width, height, name) {
	if (url) {
		var params = "resizable=yes,scrollbars=yes,status=yes";
		if (!isNaN(width)) {params += ",width=" + width;}
		if (!isNaN(height)) {params += ",height=" + height;}

		var newWindow = window.open(url, name, params);
		return newWindow;
	}
	return false;
}

function emoticon(text) {
  var txtarea = document.kniha.text;
  text = ' ' + text + ' ';
  if (txtarea.createTextRange && txtarea.caretPos) {
    var caretPos = txtarea.caretPos;
    caretPos.text = caretPos.text.charAt(caretPos.text.length - 1) == ' ' ? text + ' ' : text;
    txtarea.focus();
  } else {
    txtarea.value  += text;
    txtarea.focus();
  }
}