Access denied error on updating list through custom webpart

Question

hi
I have created one webpart having multiple view option.
On selection of items from one view user is clicking on next button to get 2nd view (THis is causing postback) and on selection of 2nd view items user is clicking on next buton for 3rd view.
On third view he can see the submit button. On click on submit button the selected items are updateing in one list and also updating data in other lists.
The list in which we are updating data have limited access to all users. But previously user were able to upate the list.
But after implimenting this multiple view with next button which  postbacks on click user are getting access denied error while updating the list. If i provide contribute access to that list then they able to submit the changes properly. But even after
that they got the error at first time.
Any body got this type of issue?
Is the post back on custom webpart cause access denied error?
i have written my code like this to updat list,
protected void btnUpdate_Click(object sender, EventArgs e)
try
SPSite site = new SPSite(SPContext.Current.Site.ID);
SPWeb myWeb = site.OpenWeb(SPContext.Current.Web.ID);
SPSecurity.RunWithElevatedPrivileges(delegate()
using (SPSite ElevatedSite = new SPSite(site.ID))
using (SPWeb ElevatedWeb = ElevatedSite.OpenWeb(myWeb.ID))
ElevatedSite.AllowUnsafeUpdates = true;
ElevatedWeb.AllowUnsafeUpdates = true;
//code to update multiple lists
catch (Exception ex)
Please suggest any solution for this.

Answer 1

Yes I checked with ULS log viewer.
Its very helpfull as reading that text log file is very difficuelt.
I found that if user spend more time on that webpart then session veriables on that webpart gets expired and at the time of redirection of user to newly created list using below code currentNewList becomes empty and its redirection to wrong list(_abc) which
is dummy list and user dont have any access.
currentNewList = NewListName+ "_abc"
SPUtility.Redirect(currentNewList.DefaultViewUrl, SPRedirectFlags.Default, HttpContext.Current);
So I modified the code to reload the session data when user clisk on submit button.