function insert(aTag, eTag) {
   var input = document.forms['gbInput'].elements['txtEntry'];
   input.focus();
   if(typeof document.selection != 'undefined') {  /* IE*/
      var range = document.selection.createRange();
      var insText = range.text;
      range.text = aTag + insText + eTag;
      range = document.selection.createRange();
      if (insText.length == 0) {
         range.move('character', -eTag.length);
      } else {
         range.moveStart('character', aTag.length + insText.length + eTag.length);
      }
      range.select();
   } else if(typeof input.selectionStart != 'undefined') {
      var start = input.selectionStart;
      var end = input.selectionEnd;
      var insText = input.value.substring(start, end);
      input.value = input.value.substr(0, start) + aTag + insText + eTag + input.value.substr(end);
      var pos;
      if (insText.length == 0) {
         pos = start + aTag.length;
      } else {
         pos = start + aTag.length + insText.length + eTag.length;
      }
      input.selectionStart = pos;
      input.selectionEnd = pos;
   } else {  /* andere Browser */
      var pos;
      var re = new RegExp('^[0-9]{0,3}$');
      while(!re.test(pos)) {
         pos = prompt("Einfügen an Position (0.." + input.value.length + "):", "0");
   }
   if(pos > input.value.length) {
      pos = input.value.length;
   }
   var insText = prompt("Bitte geben Sie den zu formatierenden Text ein:");
   input.value = input.value.substr(0, pos) + aTag + insText + eTag + input.value.substr(pos);
   }
}

function setAvatar($pic)
{
   $myPic = 'url("./files/addons/guestbook/avatar_' + $pic + '.png")';
   document.getElementById("avatarNow").style.backgroundImage = $myPic;
   document.getElementById("txtAvatar").value = $pic;
   document.getElementById('avatarChoose').style.visibility = 'hidden';
}