Hi everyone, i am looking for help on programming in TI Nspire software for a validation project. Since 'TI cares' doesn't really give any practical programming support, I came here hoping for help/answers. Basically, I need to learn more about little things to pay attention to, to make my programs work properly. Below i have put a program written to calculate a standard deviation value based on two input values, but there seems to be a glitch in there somewhere, and i don't recognize it. Code ( (Unknown Language)): Define LibPub stddevcontrol()= Prgm :Define Local odc1, odc2 :Request "OD 1 control?", odc1 :Request "OD 2 control?", odc2 :Define Local stdctrl=stDevPop(odc1,odc2) :Disp "Standard Deviation of first control=",stdctrl :EndPrgm Does anyone have an idea about the flaw in here? Thanks everyone!