XML : XSD with strict combination

i have a little problem with an exisiting XSD and an additional rule I want to implement. Here's a part of my original XSD:

  <xs:complexType name="action">      <xs:simpleContent>          <xs:extension base="xs:string">              <xs:attribute name="actid" type="xs:string" use="required" />              <xs:attribute name="acttyp" type="acttype" use="required"/>          </xs:extension>      </xs:simpleContent>  </xs:complexType>    <xs:simpleType name="acttype">      <xs:restriction base="xs:string">          <xs:enumeration value="type1" />          <xs:enumeration value="type2" />          <xs:enumeration value="type3" />          <xs:enumeration value="type4" />      </xs:restriction>  </xs:simpleType>    

So you see there are actions with different actiontypes I defined. Now there is a new rule, if there is a special actid, let's take "123", than there is only type1 permitted. So to show you:

  <action actid="123" acttype="type1">   =  permitted  <action actid="234" acttype="type1">   =  permitted  <action actid="234" acttype="type2">   =  permitted  <action actid="123" acttype="type2">   =  forbidden    

Is there a way to do this with xsd? I don't know how to combinate the enum with that rule. Anybody can help me?