Hi guys: I run the fellowing code with windows IDL 8.2 and get errors: IDL> data = RANDOMU(s,10) IDL> b = BARPLOT(indgen(10)+2, data, FILL_COLOR='red') IDL> IDL> data1 = RANDOMU(s,10) IDL> b.setData, indgen(10)+3, data1 % Loaded DLM: XML. % IDLGRPOLYLINE::SETPROPERTY: Error, invalid connectivity list detected (invalid vertex reference). % IDLGRPOLYLINE::SETPROPERTY: Error, invalid connectivity list detected (invalid vertex reference). % IDLGRPOLYLINE::SETPROPERTY: Error, invalid connectivity list detected (invalid vertex reference). So where the problem. How can I fix this? Dave