UPDATE
  taProspect
SET
  ProspectName         = @aProspectName,
  ProspectTypeID       = @nProspectTypeID,
  LabourNetBranchID    = @nLabourNetBranchID,
  DateCreated          = IF(DateCreated IS NULL, CURDATE(), DateCreated),
  OriginID             = @nOriginID,
  OriginDetail         = @aOriginDetail,
  IntroducingClientID  = @nIntroducingClientID,
  IndustryID           = @nIndustryID,
  SubIndustryID        = @nSubIndustryID,
  SalesReferrerID      = @nSalesReferrerID,
  ClientID             = @nClientID,
  LastChangeDate       = CURDATE()
WHERE
  (ProspectID = @nProspectID)
