function tag_add(obj, str1, str2){
obj.focus(); 
// Äëÿ IE
if(document.selection) 
 {
 var s = document.selection.createRange();
 if(s.text)
  {
  s.text = str1 + s.text + str2;
  s.select();
  }
 else
  {
  s.text = "";
  s.text = str1 + s.text + str2;
  s.select();
  }
 return true;
 }
// Opera, FireFox
else if (typeof(obj.selectionStart) == "number")
 {
 if (obj.selectionStart != obj.selectionEnd)
  {
  var start = obj.selectionStart;
  var end = obj.selectionEnd;
  s = obj.value.substr(start,end-start);
  obj.value = obj.value.substr(0, start) + str1 + s + str2 + obj.value.substr(end);
  obj.value.setSelectionRange(end,end);
  }
 else
  {
  var start = obj.selectionStart;
  var end = obj.selectionEnd;
  s = "";
  obj.value = obj.value.substr(0, start) + str1 + s + str2 + obj.value.substr(end);
  obj.value.setSelectionRange(end,end);
  }
 return true;
 }
 return false;
}