Handling ASP.NET Session Issues Across Multiple Browser Tabs: Ensuring Correct User Data in Popups

In modern web applications, managing user sessions across multiple browser tabs can be tricky, especially when you want to show dynamic user data in pop-ups like an application form. In this Blog, we’ll explore a common ASP.NET session issue and provide a robust solution step by step.

The Scenario

Imagine this situation:

  1. Tab 1: User A logs in.

  2. Tab 2: User B logs in in the same browser.

  3. You return to Tab 1 and try to apply IPO.

Problem

  • The pop-up shows User A’s name (from page load).

  • Backend, however, processes User B’s session data (because the session is shared across tabs).

This mismatch can confuse users and cause data integrity issues.

Why This Happens

ASP.NET sessions are per browser, not per tab.

  • Tab 1: logs in as User A → Session["ClientFname"] = "A".

  • Tab 2: logs in as User B → Session["ClientFname"] = "B".

  • Both tabs now share the same session cookie.

Result: Frontend shows old cached data (User A), while the backend processes the latest session (User B).

Goal

We want to ensure that:

✅ The frontend popup always shows the correct client details.
✅ The backend request corresponds to the same user shown in the pop-up.

Solution: Fetch Data Dynamically from Backend

The most reliable approach is to fetch user session data dynamically from the server when the pop-up is triggered. This ensures the displayed data always matches the backend session.

Step 1. Add a WebMethod in ASP.NET

In your ASPX code-behind, create a WebMethod to return session data:

[System.Web.Services.WebMethod]
public static object GetClientSessionData()
{
    try
    {
        string name = HttpContext.Current.Session["ClientFname"]?.ToString() ?? "";
        string pan = HttpContext.Current.Session["Pan"]?.ToString() ?? "";
        string dp = HttpContext.Current.Session["Depository"]?.ToString() ?? "";

        return new
        {
            ClientFname = name,
            Pan = pan,
            Depository = dp
        };
    }
    catch (Exception ex)
    {
        return new { Error = ex.Message };
    }
}

Tip: You can also create a strong-typed class for clarity instead of returning an anonymous object.

Step 2. Call the WebMethod from JavaScript

When the user clicks Apply IPO, call the WebMethod to get the current session data:

function submitalldata() {
    // Get UPI ID entered by user
    var UPIID = document.getElementById("<%=txtupiid.ClientID%>").value;

    // Call backend WebMethod to get session data
    $.ajax({
        type: "POST",
        url: "ApplyIPO.aspx/GetClientSessionData",
        data: '{}',  // no parameters needed
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: function (response) {
            var data = response.d;

            if (data.Error) {
                alert("Error: " + data.Error);
                return;
            }

            // Populate popup fields with session data
            document.getElementById("clname").innerText = data.ClientFname;
            document.getElementById("clpan").innerText = data.Pan;
            document.getElementById("cldpid").innerText = data.Depository;
            document.getElementById("clupi").innerText = UPIID;
            document.getElementById("clupiname").innerText = data.ClientFname; // optional if needed

            // Show popup modal dynamically
            $('#conformModalpopup').modal('show');
        },
        error: function (xhr, status, error) {
            console.error("Error fetching session data:", error);
        }
    });

    // Prevent full postback
    return false;
}

Step 3. What Happens Now

  • The popup always fetches current session data from the backend.

  • Even with multiple tabs open, the correct user details are shown.

  • You avoid mismatches between frontend and backend.

ASPX Markup (Frontend)

<!-- Apply Button -->

<div class="modal-footer">

<a id="applybtn" runat="server" onclick="return submitalldata();">APPLY</a>

</div>

<!-- Popup Modal -->

<div class="modal fade" id="conformModalpopup" role="dialog" aria-labelledby="exampleModalCenterTitle">

<div class="modal-dialog modal-dialog-centered" role="document">

<div class="modal-content newboarderradius modalfooterclass">

<div class="modal-header popupheader">

<h5 class="modal-title"><b>Client Details Verification</b></h5>

<button type="button" class="close clientpopupclose btn-close" data-bs-dismiss="modal" aria-label="Close">

<span>&times;</span>

</button>

</div>

<div class="modal-body">

<div class="verification">

<table class="usertblvalidation">

<tr>

<td class="useralignment">Client Name</td>

<td>:</td>

<td id="clname" runat="server" class="useralignment"></td>

</tr>

<tr>

<td class="useralignment">Pan No</td>

<td>:</td>

<td id="clpan" runat="server" class="useralignment"></td>

</tr>

<tr>

<td class="useralignment">DP ID</td>

<td>:</td>

<td id="cldpid" runat="server" class="useralignment"></td>

</tr>

<tr>

<td class="useralignment">UPI ID</td>

<td>:</td>

<td id="clupi" class="useralignment"></td>

</tr>

<tr>

<td class="useralignment">UPI ID Name</td>

<td>:</td>

<td id="clupiname" class="useralignment"></td>

</tr>

</table>

</div>

</div>

<div class="modal-footer verifiedfooter">

<div class="footerbtnopenclose">

<button type="button" class="btn btn-white verificationpopup" data-bs-dismiss="modal" id="cancelbtn">Cancel</button>

<button type="button" class="btn btn-white modify-popup verificationpopup" id="confirm_txt" onclick="message();">Confirm</button>

</div>

<div class="input-container upidivcontent">

<label id="conform_txtbx"></label>

</div>

</div>

</div>

</div>

</div>

How It Works

  1. You click “APPLY”.

  2. submitalldata() runs → calls backend method GetClientSessionData().

  3. The server sends back the current session user info (ClientFname, PAN, etc.).

  4. JavaScript fills your modal table dynamically.

  5. Bootstrap modal (#conformModalpopup) opens showing correct data.

  6. No full postback — everything happens via AJAX.

Summary

ProblemCauseSolution
Popup shows old data, backend uses another userSession shared across tabsFetch user data dynamically from backend using AJAX
Need correct data from the backendSession injected at page load is outdatedCall GetClientSessionData() before showing the popup

By following this approach, you ensure that your IPO application pop-up always shows the correct client details, preventing confusion and maintaining data integrity.