text: function select_futures(){
    try {
      obj = document.frm_position.position_distinct;
      index = obj.selectedIndex;
      if (index == "0" || index == "1"){
        document.frm_position.position_exercise.disabled = true;
        document.frm_position.position_maturity.disabled = true;
      } else {
        document.frm_position.position_exercise.disabled = false;
        document.frm_position.position_maturity.disabled = false;
      }
    } catch(e) {
      return;
    }
  }
  
  function changeRangeValue(value) {
    document.getElementById("range_val").innerHTML = value;
  }
  
  function changeSigmaValue(value) {
    document.getElementById("sigma_val").innerHTML = value;
  }
  
  