UnknownHostException: api.search.yahoo.com

when executing YahooWebServiceParseResults.java i encountered following exception ........

Exception in thread "main" java.net.UnknownHostException: api.search.yahoo.com
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:519)
at java.net.Socket.connect(Socket.java:469)
at java.net.Socket.<init>(Socket.java:366)
at java.net.Socket.<init>(Socket.java:240)
at org.apache.commons.httpclient.protocol.DefaultProtocolSocketFactory.createSocket
(DefaultProtocolSocketFactory.java:80)
at org.apache.commons.httpclient.protocol.DefaultProtocolSocketFactory.createSocket
(DefaultProtocolSocketFactory.java:122)
at org.apache.commons.httpclient.HttpConnection.open(HttpConnection.java:707)
at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDire
ctor.java:387)
at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirecto
r.java:171)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:323)
at javaapplication1.YahooWebServiceParseResults.main(YahooWebServiceParseResults.ja
va:50)

please help .........