Dear John This sounds interesting, however, I've been struggling for quite a sometimes on limiting the number of options a user could see when it loads the tool wrapper. I have a separate database that records the results obtained from the execution of my developed tool along with the $__user_email__. This way my database table has the results for all galaxy users. My tool also let the users to perform further downstream analysis on the previous run. Therefore, I am using dynamic_options in wrapper xml to populate a dropdown with the results/datasets for the previous run of the tool to choose from. The problem is I have to show the datasets/results for all users, ideally I would like to limit the options in the dropdown to the results belonged to the logged-in user by writing a query something similar to select id, option from myTable where useremail=$__user_email__. However, I have no idea how to grab the $__user_email__ at time of execution of the function assigned via dynamic_options="load_dynamic_values()" in xml wrapper. Would you have any idea how this could be achieved. Thanks. Regards, Matloob