You probably don't remove the previously posted notification. A new notification cannot be posted until the previous one is removed with the "remove notification" command.

There is a sample script called "display better dialog" in the "Sample Scripts" folder. Open the script in your script editor, and you'll see couple of examples on how to gather data from different kinds of dialogs.

The version 1.1 of 24U SimpleDialog Plug-In introduced a new feature - text and password field validations. This new feature also brings a new limitation. If you want to use the character "{" as the first character of your default value, you must explicitly specify validation options. If you don't want to use validation, simply precede your default value with the plain format specifier "{}".

On Mac OS X, scripting additions can be installed in the "ScriptingAdditions" folder inside any active Library folder. The Library folder in the System folder is not intended for installing 3rd-party scripting additions. By default, there is no "ScriptingAdditions" folder in any other Library folder, so you need to create a new one before you install the scripting addition in it. Use the Library folder in the root directory of your startup disk if you want all users of your system to be able to use the OSAX, or the Library folder inside your home directory if you want be the only user to use the OSAX.