Bootstrap modal losing textboxvalue after postback

I have some strange behavior with a bootstrap modal, the modal contains a textbox and an asp:button

When I click the button and inspect the value of the textbox in VB code behind - results in an empty string

If I remove the first and last lines from the code below, I can successfully read the value in the textbox from code-behind

Here is the modal markup:

 <div class="modal inmodal" id="modalUpdateDialog" tabindex="-1" role="dialog" aria-hidden="true">
        <asp:UpdatePanel ID="udpUpdateDialog" runat="server" UpdateMode="Conditional">
            <ContentTemplate>
                <div class="modal-dialog">
                    <div class="modal-content animated bounceInDown">
                        <div class="modal-header">
                            <button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">×</span><span class="sr-only">Close</span></button>
                            <h4 class="modal-title">Update File</h4>
                            <small class="font-bold">Please enter your new description</small>
                        </div>
                        <div class="modal-body form-horizontal" style="height: auto; overflow: auto;">
                            <div class="form-group">
                                <label class="col-sm-2 control-label">Description</label>
                                <div class="col-sm-10">
                                    <asp:TextBox ID="txtNewDescription" runat="server" CssClass="form-control" />
                                    <asp:HiddenField ID="hdnRowID" runat="server" />
                                </div>
                            </div>
                        </div>
                        <div class="modal-footer">
                            <asp:Button ID="btnUpdateFile" runat="server" Text="Update File" class="btn btn-primary" UseSubmitBehavior="false" />
                        </div>
                    </div>
                </div>
            </ContentTemplate>
        </asp:UpdatePanel>
    </div>

Open in new window

BrianFordAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

BrianFordAuthor Commented:
FYI, I get the same issue with or without the updatePanel
BrianFordAuthor Commented:
Problem solved..

It turned out to be an issue with the Inspinia admin theme we are using, in particular the inpinia.js and jquery.slimscroll.min.js

For now we removed these and everything works great, next step is to log an issue with Inspinia :)

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
BrianFordAuthor Commented:
Only took me 2 days to find this :)
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
ASP.NET

From novice to tech pro — start learning today.