Unable to Add "Referrence" in WPF Speech Synthesizer example

Hi I am following your article very lately but very extremely, In the example “Speech Synthesizer” I got the same issue

The type or namespace name ‘SpeechSynthesizer’ could not be found (are you missing a using directive or an assembly reference?):

but in the solution explorer window upon right click its opening the My documents folder, not as you have explained in the illustration .net/COM/ … tab.

So I am unable to resolve the issue, even “using Systems.Speech” is not working.

Any help would be highly appreciated, am i doing something wrong?

Deb