I have a 'select' tag in a tool's XML file, I would like to have a default option, which is choosing nothing. So the drop down menu of the web interface will be empty and when a user clicks the drop down menu, the list contains an empty entry with other options. So I basically have an option tag like the following <option value=""></option> together with other options. This works fine when I have up to 19 options including the default options. A user can submit the job without selecting any options and the program will use the default option. However, when the number of options exceeds 20, then drop down menu of the web interface displays "Click to Select or Search" instead of empty. And the user has to select one of the options in order to submit the job, otherwise, a question mark is displayed in the drop down menu and then an error message shows up under the drop down menu with the message "An invalid option was selected, please verify".