i add table tag in storage-conf.xml:

 <Table Name="users">
     <ColumnFamily ColumnSort="Name" Name="content"/>
 </Table>

and then invoke by below program:

client.insert("users", key_user_id, "content:name", "Chris Goffinet".getBytes("UTF-8"), timestamp, false);

and then throws exception:

InvalidRequestException(why:Column Family content is invalid.)
at org.apache.cassandra.service.Cassandra$insert_result.read(Cassandra.java:5072)
at org.apache.cassandra.service.Cassandra$Client.recv_insert(Cassandra.java:303)
at org.apache.cassandra.service.Cassandra$Client.insert(Cassandra.java:276)
at com.chinaren.alumni4.cassandra.CClient.main(CClient.java:33)

please tell me why and how modify am i,thanks a lot.