Parent JSP Page is not refreshing properly after modifying a child Jsp.

Hi,

I am working on a Struts app and I am facing following problem .

Working Scenario:

I have a JSP page where I have few fields. One of the field is a hyperlink, clicking on which I get a pop-up child JSP page.
Now on that child JSP, i enter few data and save it. now this child JSP closes and parent JSP should refresh with the new data in child JSP. It is working fine if this action is done within 15 minutes.

Not working scenario:

If I leave the parent JSP page idle for more than 15 mins, and then click hyperlink, update and save the Child JSP page, the parent JSP is refreshing but the data is lost. I mean that the table data disappears, drop down values diappear and the dropdown width decreases so I can not see the options in the drop down.

What could be the cause and how to correct it? Please help.

Do you utilize sessions, cached objects, or anything that might have a lifetime? For instance, is the session populated with parameters which are lost after the session expires?

Yes I am dealing with sessions. But session time out is set to 45 mins in web.xml.

I was just wondering how come after 15 mins all the data disappears from parent JSP.