function validate_required(field)
{
with (field)
  {
  if (value==null||value=="")
    {
    alert("Debe de llenar el campo");return false;
    }
  else
    {
        //if (field.value.search(/\*/) >= 0 )
        //{
        //alert("No se permiten consultas con *");
        //return false;
        //}
        //else
        //{
        return true;
        //}
    }
  }
}

function validate_form(thisform)
{
with (thisform)
  {
  if (validate_required(keywords)==false)
  {keywords.focus();return false;}
  }
}