XML : Element Requires Further Child Elements

So I was designing an XML file based on a certain DTD. The logic is thus:

  Category >> Books >>Author[required], Price[required], Description, Image)    

Here is the DTD generated:

  <!ELEMENT CATAGORY (PRODUCT+)>  <!ELEMENT PRODUCT  (NAME,PRICE,DESCRIPTION*,PICTURE*)>  <!ATTLIST PRODUCT  NAME CDATA #REQUIRED  PRICE CDATA #REQUIRED  DESCRIPTION CDATA #IMPLIED  PICTURE CDATA #IMPLIED  CATEGORY (BOOKS|GADGETS|OTHERS) "BOOKS"  AUTHOR CDATA #REQUIRED  ISBN CDATA #IMPLIED  INVENTORY (InStock|Backordered|Discontinued) "InStock">    

However, I am unable to write a valid XML. I wrote thus:

  <CATAGORY>      <PRODUCT NAME="XML BOOK" AUTHOR="XML GENIUS" CATEGORY="BOOKS" DESCRIPTION="BRILLIANT XML BOOK."  INVENTORY="InStock" ISBN="653725327" PRICE="36.99" PICTURE=""/>      <PRODUCT NAME="XML MASTERS" AUTHOR="XML TEACHER" CATEGORY="BOOKS" DESCRIPTION="" INVENTORY="InStock" ISBN="" PICTURE="" PRICE="23.99"/>   </CATAGORY>    

I get the following error. Any help is appreciated.

  Content model of element <PRODUCT> requires further child elements.      Error location: CATAGORY / PRODUCT      Details          VC: Element Valid (2): Content model of element <PRODUCT> requires further child elements.