 The data contained in the CRF will be data entered centrally by personnel appointed thereto by the Clinical Principal Investigator by single data entry and electronic verification of data. Any text elements eg, comments will be verified manually. Data entries will subsequently be controlled by validation programs and listing controls. Obvious errors will be corrected directly by data management personnel, other errors or omissions will instead be recorded on Data Query forms which will be sent to the Investigators for resolution. 