Hi Björn, It looks like this. <tool id="screen_reads" name="Screen Reads"> <description>against hg19</description> <command interpreter="bash">screen_reads.sh $Project.input $Project.samples $Project $Samples </command> <inputs> <conditional name="Project"> <param name="input" type="select" label="Select project"> <option value="galaxy_test1">galaxy_test1</option> <option value="Untitled Folder">Untitled Folder</option> </param> <when value="galaxy_test1"> <param name="samples" type="select" label="Select samples" display="checkboxes" multiple="True"> <option value="147406386-700171390">147406386-700171390</option> <option value="158256496-700097688">158256496-700097688</option> <option value="158337416-700013715">158337416-700013715</option> <option value="158337416-700097837">158337416-700097837</option> <option value="158357646-700035237">158357646-700035237</option> <option value="158458797-700014562">158458797-700014562</option> <option value="158479027-700014724">158479027-700014724</option> <option value="158479027-700097196">158479027-700097196</option> <option value="158499257-700014837">158499257-700014837</option> <option value="158499257-700098561">158499257-700098561</option> <option value="158742018-700015181">158742018-700015181</option> <option value="158802708-700015245">158802708-700015245</option> <option value="158802708-700015250">158802708-700015250</option> <option value="158802708-700099803">158802708-700099803</option> <option value="158802708-700119165">158802708-700119165</option> <option value="158822939-700014954">158822939-700014954</option> <option value="158883629-700015113">158883629-700015113</option> <option value="158883629-700100227">158883629-700100227</option> <option value="158883629-700112812">158883629-700112812</option> <option value="158924089-700099307">158924089-700099307</option> </param> </when> <when value="Untitled Folder"> <param name="samples" type="select" label="Select samples" display="checkboxes" multiple="True"> </param> </when> </conditional> </inputs> <outputs> <data format="tabular" name="Project" label="Project" from_work_dir="/eva/projects/smash/MOCAT/test/martin/$Project.input/$Project.input"/> <data format="tabular" name="Samples" label="Samples" from_work_dir="/eva/projects/smash/MOCAT/test/martin/$Project.input/$Project.samples"/> </outputs> <help> Reads screened against hg19. </help> </tool> Best, Martin