Hi all, I am trying to format the input to a java tool that I am writing. I want to display different options to choose from based on the user input. I am not sure how to do that. For example, based on the input file, I want to display the chromosome options to choose from. How do I do this? <param name="input_bam_file" type="data" format="BAM" label="Input BAM file" help="Choose an input BAM file"/> <param name="chromosome_options" type="select" label="Choose the chromosome"> <option value="1"> chr1 </option> <option value="2"> chr2 </option> </param> I am not sure how to call a program that will generate the second input based on the first one and then wait for the user to choose the rest of the input and then run another program. Thanks, VJ.