function insertAtCursor(myField, myValue) {
  //IE support
  if (document.selection) {
    myField.focus();
    sel = document.selection.createRange();
    sel.text = myValue;
    myField.focus();
  }
  //MOZILLA/NETSCAPE support
  else if (myField.selectionStart || myField.selectionStart == '0') {
    var startPos = myField.selectionStart;
    var endPos = myField.selectionEnd;
    var scrollTop = myField.scrollTop;
    myField.value = myField.value.substring(0, startPos)
                  + myValue 
                      + myField.value.substring(endPos, myField.value.length);
    myField.focus();
    myField.selectionStart = startPos + myValue.length;
    myField.selectionEnd = startPos + myValue.length;
    myField.scrollTop = scrollTop;
  } else {
    myField.value += myValue;
    myField.focus();
  }
}