Question

How to access or get reference of control in UpdatePanel through javascript?

Answer 1

A control in an UpdatePanel is no different than a control on any other page so you can access them in the same way. The difference is that an UpdatePanel can have new controls added constantly with no easy way for you to get the ClientID of the control on the fly as the UpdatePanel updates. In these cases I have used a unique style name (style doesn’t have to have any details, it’s just used as a tag in this case) and access it using jQuery’s style accessor. It’s not very often that I have to resort to this method but when I have had to style names were sufficient.

// Will get the control with this specific style
$(".YourControlsUniqueStyleName")

EDIT:

In your control add the following to the CssClass:

<asp:TextBox ID="TextBox1" runat="server" CssClass="YourControlsUniqueStyleName"></asp:TextBox>

Then with javascript using jQuery you can access the control with the css class name directly like so and read the value:

var TextBox1Value = $(".YourControlsUniqueStyleName").val();

Hope that helps.