function validate_formus ( )
{
	valid = true;
        if ( document.contact_us.tel.value == "" )
        {
                alert ( "Please enter a value for the 'UK Landline' field." );
                valid = false;
        }
        if ( document.contact_us.email.value == "" )
        {
                alert ( "Please enter a value for the 'E-Mail' field." );
                valid = false;
        }
        if ( document.contact_us.chargesy.checked == false )
        {
                alert ( "Please check the 'Yes I have read your charges page' box." );
                valid = false;
        }
        return valid;
}