Problem running servlet in netbeans

[warlord902]

I have got everything right and my project is compiling. But I am experiencing problem with servlets, when I right click on a servlet and click on run in netbeans then I get following two error:
1) Class "Servlet1" neither has a main method not it a servlet specified in web.xml
2) Class "Servlet1" does not have a main method.

My serlvet is defined in web.xml, i have checked it in web.xml:

<servlet>
        <servlet-name>Servlet1</servlet-name>
        <servlet-class>Servlet1</servlet-class>
    </servlet>
<servlet-mapping>
        <servlet-name>Servlet1</servlet-name>
        <url-pattern>/Servlet1</url-pattern>
    </servlet-mapping>

And our teacher was running servlet without any main method, so I can't figure out what is wrong with it?

[peter_budo]

Did you associated your project with an instance of Tomcat?

[warlord902]

Did you associated your project with an instance of Tomcat?

It started working after I restarted netbeans, must be some problem with it only.

[peter_budo]

Be careful sometimes IDE fail to shut down Tomcat. Then you will get error as "can't start, port in use" or similar

[warlord902]

Be careful sometimes IDE fail to shut down Tomcat. Then you will get error as "can't start, port in use" or similar

ok, thanks
I'll take care of it.