__doPostBack is not defined

Question

Im getting that error when try to call a __doPostBack on one of my pages, every page that i have in the project use __doPostBack function but in this particular page im getting that Javascript error.

i was looking in the internet and the only thing i read is that this error happends when i have a unclose tag but i review the site and its ok.

Error: __doPostBack is not defined Source File: htt://localhost:99/ProjectName/Disable.aspx Line: 1

Answer 1

I was getting this because my script was inside an Iframe that was being "disposed" (it was a Telerik "window" that was closed). The code defining _dopostback() inside my iframe was gone, but the code calling _dopostback() inside my iframe was still hanging around. Love that JavaScript!

Answer 2

Wrapping my server side controls in a form element with runat="server" attribute worked for me. According to asp environment there should be only one form element with runat="server" attribute in it otherwise some serious issue may happen.

<form runat="server" id="form1">
   <!-- Server side controls go here -->
</form>

Answer 3

i used this method in my script that included to asp.net form:

main form id sample:
<script src="myscript" />

<form id="frmPost" runat="server">
</form>

// myscript.js in java script function
mypostboack: function () {
$('#frmPost').context.forms[0].submit()
}

Answer 4

For me it was the following was missing from the page:

<form runat="server">
</form>

Answer 5

Here's why this was happening to me: I accidentally forgot that script tags must always have closing tags:

<script src="/Scripts/appLogic/Regions.js" />

I corrected the script tag:

<script src="/Scripts/appLogic/Regions.js" type="text/javascript" ></script>

and sanity returned.

Answer 6

__doPostBack Works guys

Write this code in Page Load

ClientScript.GetPostBackEventReference(this, "");