In Dialog Activity step add Attachments?

Hi experts,

Here is the requirement:

I want to create a Dialog Activity step, When ever approver execute the WI: i need pop up window to add information and need to add attach documents.

Can you please help me. It is urgent.

These information and attachments how to store in workflow container?

and these are need to pass in to  another User decission step?  how to achieve this?

Thanks in advance