WebForm_PostBackOptions is undefined

[Guest]

Hi!

I have a simple page, created in VS2005 and C#. It has a textbox,
requiredfieldvalidator and a linkbutton, when I click the linkbutton I get
the javascript error
'WebForm_PostBackOptions' is undefined, but if I add or replace the
linkbutton with a regular button it works fine.
The debugger stops at this row::
WebForm_DoPostBackWithOptions(new
WebForm_PostBackOptions("ctl00$ContentPlaceHolder1$LinkButton1", "", true,
"steg2", "", false, true))

How can I solve this?

 

[Guest]

Should add that if I add a button instead of replaceing the linkbutton, both
will work fine!

Regards
Anders Aleborg