Thank to Community Mapbuilder and CS. I learned a lot from Mapbuilder. Bui Hong Son Deputy Chief of SCIREN http://ciren.vn http://www2.hcm.ciren.gov.vn/cirengis No virus found in this outgoing message. Checked by AVG. Version: 7.5.524 / Virus Database: 270.5.6 - Release Date: 7/25/2008 12:00 AM