How to get Session ID?

We have used JSP to read the session id into an instance.

<session-instance>

    <form-id><%=session.getId()%></form-id>

</session-instance>

The session instance is read in from a JSP file:

<xforms:instance id="session-instance" src="../xforms-jsp/personal-loan-app/sessionInstance.jsp"/>                              

We then submit the data to an exist database using the session id as part of the file name to get a unique database.

<xforms:submission       id="save-data"

    ref="instance('details-instance')"

    resource="/exist/rest/db/orbeon/personal_loan{instance('session-instance')/form-id}.xml"

    method="put"

    replace="none"

    relevant="false">

</xforms:submission>

<!-- load the data from an exist database so when go back and forth the data can be viewed -->

<xforms:submission       id="load-data"

    serialization="none"

    method="get"

    resource="/exist/rest/db/orbeon/personal_loan{instance('session-instance')/form-id}.xml"

    replace="instance"

    instance="details-instance"

    validate="false"/>                             

<!-- load the data on load -->

<xforms:send ev:event="xforms-ready" submission="load-data"/>

We have a multipage form and are currently saving data every time a user navigate to next/previous page.

The problem is: it is saving the data fine but it does not load the data on the next page. The same code works when saving and loading to a static database name (same database for all users, using no session id). Any ideas?

Is there a better way to get the session id? Maybe there is a better way to save data into a user-unique database?

Much appreciated,

Trond & Serena