function my_options(value, text)
{
  this.value=value;
  this.text=text;

  return this;
}  

function change_options(opt_name, master, name_slave, index_master)
{
  val_master=master.options[index_master].value;
  slave=eval("master.form."+name_slave);
  cmd=opt_name+'[val_master].length'
  var opt_slave_length=eval(cmd);
  slave.options.length=opt_slave_length;
  for (i=0; i<opt_slave_length; i++ ) {
    slave.options[i].value=eval(opt_name+'[val_master][i].value');
    slave.options[i].text=eval(opt_name+'[val_master][i].text');
  }
  slave.selectedIndex=0;
  
}