Updatepanel not updating
The Content Template tag is required, since it holds the content of the panel.The content can be anything that you would normally put on your page, from literal text to web controls.So, In case we have multiple control that we need to update we can use the control name to retrieve the value form the Controldata Items.Hope this gives you a good idea that what needs to do to update controls which is outside of updatepanel during partial page rendering. This will ensure that the first panel is updated even when a control on a different Update Panel is used.The Async Post Back Trigger tag is pretty simple - it only takes two attributes, the controlid, a reference to the control which can trigger it, and the eventname, which tells which eventtype can cause the trigger to fire.
The following example will show the use of both childtags. As you can see, the first Update Panel carries a trigger which references the second button.
We already used it in the Hello world example, and in this chapter, we will go in depth with more aspects of the control.
The tag has two childtags - the Content Template and the Triggers tags.
If you wish for the content of a Update Panel to be updated no matter what, you may change the updatemode property to Always.
In general, you should only have Update Panels areound areas where you wish to do partial updates.