<p>I'm having a strange problem.</p>

<p>I have to use <code>GetPostBackEventRefence</code> to force a Postback, but it works the first time, after the first postback, the .NET function is not rendered... any ideas?</p>

<p>This is what I'm missing after the postback:</p>

<pre><code>&lt;script language="javascript" type="text/javascript"&gt;
&lt;!--
function __doPostBack(eventTarget, eventArgument) {
    var theform;
    if (window.navigator.appName.toLowerCase().indexOf("microsoft") &gt; -1) {
        theform = document.Main;
    }
    else {
        theform = document.forms["Main"];
    }
    theform.__EVENTTARGET.value = eventTarget.split("$").join(":");
    theform.__EVENTARGUMENT.value = eventArgument;
    theform.submit();
}
// --&gt;
&lt;/script&gt;
</code></pre>

The first thing I would look at is whether you have any asp controls (such as linkbutton, comboboxes,that don't normally generate a submit but requre a postback) being displayed on the page.
The __doPostback function will only be put into the page if ASP thinks that one of your controls requires it.
If you aren't using one of those you can use:
```
```
Page.ClientScript.GetPostBackClientHyperlink(controlName, "")
```
```
to add the function to your page