function validate_form ( )
{
    valid = true;

    if ( document.contact_form.fname.value == "" )
    {
        alert ( "Favor de dar su primer nombre." );
        valid = false;
    }

	 if ( document.contact_form.lname.value == "" )
    {
        alert ( "Favor de dar su apellido." );
        valid = false;
    }


	if ( document.contact_form.email.value == "" )
	{
        alert ( "Favor de dar su email." );
        valid = false;
    }

   return valid; 
   
}