Hello, I am building a tool config, and I am looking for a way to have nested conditionals being automatically selected based on a previous conditional. Schematically it looks like this: Choose: option 1 or option 2 if option 1: no extra parameters if option 2: extra parameters to set Choose: additional option A or B if additional option A: no extra parameters if additional option B: set extra parameter Choose: option 1 or option 2 (<--------------) if option 1: one extra parameter to set if option 2: two other extra parameters to set Nested options are possible (indicated by <----------------). However, instead of again choosing the same option as in the first conditional, the outcome of the nested conditional should be the same already known. It is no option to reverse conditional A/B with conditional 1/2. In Galaxy syntax it looks like: (note that the last, nested, conditional is the same as the first conditional) <conditional name='*condition12*'> <param name="condition" type="select"> <option value="1" selected="True">1</option> <option value="2" >2</option> </param> <when value='1'/> <when value='2'> <param name='extra1' .../> <param name='extra2' .../> </when> </conditional> <conditional name="conditionAB"> <param name="condition" type="select"> <option value="A" selected="True">A</option> <option value="B">B</option> </param> <when value="A"/> <when value="B"> <param name="extra4" .../> <conditional name='*condition12*'> <param name="condition" type="select"> <option value="1" selected="True">1</option> <option value="2" >2</option> </param> <when value='1'> <param name='extra5' .../> </when> <when value='2'> <param name='extra6' .../> <param name='extra7' .../> </when> </conditional> </conditional> The goal is to get automatically the nested conditional right (condition12), based on the selection the user makes in the first conditional. Any hint on how to get this right? Regards, Joachim -- Joachim Jacob, PhD Rijvisschestraat 120, 9052 Zwijnaarde Tel: +32 9 244.66.34 Bioinformatics Training and Services (BITS) http://www.bits.vib.be @bitsatvib