Step to Use of Servlet in Tomcat Server in Eclips IDE:
If you are using Eclipse IDE first time, you need to configure the tomcat
For configuring the tomcat server in eclipse IDE, click on servers tab at the bottom side of the IDE -> right click on blank area -> New -> Servers -> choose tomcat then its version -> next -> click on Browse button -> select the apache tomcat root folder previous to bin -> next -> addAll -> Finish.
Select --->tomcat server7.0.....
tomcat server configuration is one time only not always...
Now tomcat7 server has been configured in eclipse IDE.