Why is 'BusyIndicator' not found?

I am using Silverlight 5 toolkit and I am references that version of Silverlight.Windows.Controls.Toolkit in my silverlight demo.

But I get this error and I do not know what to do

Error 16 The tag 'BusyIndicator' does not exist in XML namespace 'clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Toolkit'. C:\Users\Bobbi\Documents\Visual Studio 2012\Projects\...

How do I get the code to compile?

https://www.google.com/search?q=%22Why% ... ound%3F%22

Please stop posting your non-game programming questions on the GPWiki forum. It's sad enough that you don't put in the simple effort of finding your own answers through google but then spamming the same question across multiple forums while contributing nothing back to the community just demonstrates a supreme arrogance.

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Whatever the mind can conceive and believe, it can achieve

You are wrong. All programming questions are game related programming questions. Games require all the same sort of components that any Silverlight or C# program might have.

You are also wrong about google or search engines. I first try to find the answer googling and often get conflicting answers.

And you do not really understand what spamming is. Getting different opinions is not spamming.