javascript - OnSelectedIndexChanged not firing once deployed -

I'm not the first to choose, the on-selected index is not firing in IE, once deployed:

And much more.

Here's my code:

  & lt; Asp: Dropdown List ID = "MyDropDownList" Runat = "Server" & gt; & Lt; Asp: ListItem text = "life" value = "1" /> & Lt; Asp: ListItem text = "universe" value = "2" /> & Lt; Asp: ListItem text = "everything" value = "42" /> & Lt; / Asp: DropDownList & gt;  

More:

Secure Override Zero OnInit (EventArgs e) {MyDropDownList.AutoPostBack = true; MyDropDownList.SelectedIndexChanged + = New EventHeader (MideropdownListSactedEndended); } Protected Zero MyDropDownListSelectedIndexChanged (Object Sender, EventArgs e) {// Many Things}

Now we move the results into HTML .

Here's with Chrome, (or IE with compatibility mode):

  & lt; Select name = "MIDOPRODOWNIST" onchange = "javascript: setTimeout ('__ doPostBack (...)', 0)" ID = "MyDropDownList" & gt; & Lt; Option value = "1" selected = "selected" & gt; Life & lt; / Options & gt; & Lt; Option value = "2" & gt; Universe & lt; / Options & gt; & Lt; Option value = "42" & gt; Everything & lt; / Options & gt; & Lt; / Select & gt;  

And here it is with IE10 / IE11 (without compatibility):

  & lt; Name name = "MyDropDownList" id = "MyDropDownList" & gt; & Lt; Option value = "1" selected = "selected" & gt; Life & lt; / Options & gt; & Lt; Option value = "2" & gt; Universe & lt; / Options & gt; & Lt; Option value = "42" & gt; Everything & lt; / Options & gt; & Lt; / Select & gt;  

Wonder!
onchange attribute gone !

OK ...
Now I know why the incident is not firing from IE.
... but why is it explained in a different way?

Important Details: This is posted only once on the server (I believe it is IIS 6). Locally, it works fine.

Another important detail: Installing any kind of patches is unfortunately not an option for me.

Why do not you do this:

  & asp: dropdown list ID = "MyDropDownList" runat = "server" autopostback = Indexes selected on "right" switch = "MyDropDownListSelectedIndexChanged" & gt; & Lt; Asp: ListItem text = "life" value = "1" /> & Lt; Asp: ListItem text = "universe" value = "2" /> & Lt; Asp: ListItem text = "everything" value = "42" /> & Lt; / Asp: DropDownList & gt;  

and on the server side:

  Protected Zero MyDropDownListSelectedIndexChanged (Object Sender, EventArgs E) {// do stuff here}