// Funkce insertAtcursor() prevzata z URL http://www.webmasterworld.com/forum91/4686.htm
// dekuji uzivateli ajkimoto za kod.
//myField accepts an object reference, myValue accepts the text strint to add
function insertAtcursor(myField, myValue) {
  //IE support
  if (document.selection) {
    myField.focus();
    
    //in effect we are creating a text range with zero
    //length at the cursor location and replacing it
    //with myValue
    sel = document.selection.createRange();
    sel.text = myValue;
  }
  
  //Mozilla/Firefox/Netscape 7+ support
  else if (myField.selectionStart || myField.selectionStart == '0') {
      //Here we get the start and end points of the
      //selection. Then we create substrings up to the
      //start of the selection and from the end point
      //of the selection to the end of the field value.
      //Then we concatenate the first substring, myValue,
      //and the second substring to get the new value.
      var startPos = myField.selectionStart;
      var endPos = myField.selectionEnd;
      myField.value = myField.value.substring(0, startPos)+ myValue+ myField.value.substring(endPos, myField.value.length);
    } else {
      myField.value += myValue;
  }
  myField.focus();
}