You may receive this error in the browser using Internet Explorer 10:
“Script Error encountered”, “‘__doPostBack’ is undefined”
Fixes are now available for Microsoft .NET Framework 3.51 (Windows 7 / Windows Server 2008 R2), Microsoft .NET Framework 4.0 and Microsoft .NET Framework 2.0 SP2:
http://support.microsoft.com/kb/2600088 (.NET Framework 4.0)
http://support.microsoft.com/kb/2608565 (Win7/Server 2008 R2 )
http://support.microsoft.com/kb/2600100 (.NET Framework 2.0 SP2/.NET Framework 3.5 SP1)
In addition, the Microsoft .NET Framework 4.0 fix addresses an issue in which the browser’s scroll position is not maintained after a postback even though you’ve set the MaintainScrollPositionOnPostBack in your web application code.
To get the appropriate fix, go to the appropriate article and click the “Hotfix Download Available” graphic and follow the instructions: