movie dtd

[musicmancanora4]

Basically im trying to design a dtd that represents a collection of movies
Not sure why but when i try validate the dtd it says undetermined element declaration
'Movies' but i have declared it havnt i?

could someone take a look at my code give me some pointers ? thanks

<!--Compulsary to have a movie name-->
<!ELEMENT Movies (movie_name)(#PCDATA) #REQUIRED>

<!--Optional to have distributer listed-->
<!ELEMENT Distributor (#PCDATA) #IMPLIED>

<!--Compulsary to have a first and last name
  for lead actors-->
<!ELEMENT Lead_Actors (First) (Last) #REQUIRED>
<!ELEMENT First (#PCDATA)>
<!ELEMENT Last  (#PCDATA)>

<!--one of more reviews including-->
<!ELEMENT Review_Info(Rev_Name+,Star_Rat+,
		  Text+)
<!ELEMENT Rev_Name(#PCDATA)>
<!ELEMENT Star_Rat(#PCDATA)>
<!ELEMENT Text(#PCDATA)>

<!--reference to other movies the actor is in-->
<!ATTLIST Move id ID #IMPLIED title CDATA #IMPLIED>
<!ATTLIST Other_Movies IDREF REQUIRED#>
          
<!--Specify the suitable audience rating-->
<!ELEMENT Rating(G,PG, M , R)>
<!ELEMENT G(#PCDATA)>
<!ELEMENT PG(#PCDATA)>
<!ELEMENT M(#PCDATA)>
<!ELEMENT R(#PCDATA)>

<!--Cinemas the movie is being showed at-->
<!ELEMENT CINEMA_NAME(#PCDATA)>