SSIS is not designed for and should not be used for processes that have to stop mid-stream and wait for user input.
Modify your package to use a package variable and prompt the user for the input before starting the package - then you can pass in the information through the SET values in the package. Also keep in mind that an SSIS package can only be run on an SSIS Server. If you include an SSIS package in an application and the application runs locally on a users workstation, you will have to install an SSIS server on each workstation that runs the package (and license it).
If you have a workflow that needs input mid-stream, I would suggest you look into a business workflow package like BizTalk.