Hi, I encounter a stange problem. The boolean variable "shift_cor" is "true" shift_cor :boolean; writeln('shift_cor: ',true); { shift_cor: True } if shift_cor=true then Shift_correction; But the if statement does not work out to be "true" as the procedure "Shift_correction" does not run. Anyone an idea what is wrong here? Thanks! Casper. Casper ter Kuile, Lab. for Radiation Research (LSO), National Institute of Public Health and the Environment (RIVM) PO box 1, NL-3720 BA, Bilthoven, the Netherlands Phone +(31)-30-2742647 or +(31)-30-2742515 E-mail: casper.ter.kuile@rivm.nl Web: http://www.rivm.nl