problem with socket

hi all,

First of all, I am a newbie in programming, and I have to make a simple tcp/ip (hello replied) server.
I am trying to follow the tutorial ini here : http://www.c-sharpcorner.com/uploadf...tserverst.aspx

to make a server. However, when I tried to do it in the ide (visual studio 2008), I got an error bellow
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Error 1 Program 'C:\Users\reza\Documents\Visual Studio 2008\Projects\WpfApplication2\WpfApplication2\obj\Debug\WpfApplication2.exe' has more than one entry point defined: 'WpfApplication2.App.Main()'. Compile with /main to specify the type that contains the entry point. C:\Users\reza\Documents\Visual Studio 2008\Projects\WpfApplication2\WpfApplication2\obj\Debug\App.g.cs 59 28 WpfApplication2

Error 2 Program 'C:\Users\reza\Documents\Visual Studio 2008\Projects\WpfApplication2\WpfApplication2\obj\Debug\WpfApplication2.exe' has more than one entry point defined: 'serv.Main()'. Compile with /main to specify the type that contains the entry point. C:\Users\reza\Documents\Visual Studio 2008\Projects\WpfApplication2\WpfApplication2\Window1.xaml.cs 8 24 WpfApplication2
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It seems that there are to main functions, one in App.g.cs and the other one in Window1.xaml.cs. How am I supposed to fix this? I am sorry, but if it's possible, I would very appreciate if you use a simple language for explanation (not too high, I am still trying to grasp this language..)

Thank you