how can i include username and password

Hi,

Login forms are actually prohibited as per our terms of use:

http://www.jotform.com/terms/

Our forms can only be used to collect data and do not reference a database upon submission, they only store the data.  For this reason having a username and password field would only collect this data, not allow user to login.  

Let us know if you have any further questions and we will be happy to help.