Sorry Em16 : : Sorry Why i got these. . . - --------------------Configuration : Hello-JDK version "Default>;-------------------- C:\test\Hello\Hello.java:41 can not resolve symbol : Symbol : 14.00 ImageIcon Location : 14.00 JCTX ImageIcon ii; ^ C:\test\Hello\Hello.java:42 can not resolve symbol : Symbol : 14.00 JButton Location : 14.00 JCTX JButton jb; ^ C:\test\Hello\Hello.java:43 can not resolve symbol : Symbol : 14.00 Timer Location : 14.00 JCTX Timer time; ^ C:\test\Hello\Hello.java:50 can not resolve symbol : Symbol : class JFrame Location : 14.00 JCTX JFrame frame = new JFrame ( "Jincheng communications animation Oh!"); ^ C:\test\Hello\Hello.java:50 can not resolve symbol : Symbol : class JFrame Location : 14.00 JCTX JFrame frame = new JFrame ( "Jincheng communications animation Oh!");                    ^ C:\test\Hello\Hello.java:51 can not resolve symbol : Symbol : 14.00 Container Location : 14.00 JCTX Container c = frame.getContentPane (); ^ C:\test\Hello\Hello.java:53 can not resolve symbol : Symbol : 14.00 ImageIcon Location : 14.00 JCTX Ii = new ImageIcon ( "univesal_smile.gif") and Class ;// this document in a document path, it is necessary to pay attention! ! !          ^ C:\test\Hello\Hello.java:54 can not resolve symbol : Symbol : 14.00 JButton Location : 14.00 JCTX Jb = new JButton (ii);          ^ C:\test\Hello\Hello.java:55 can not resolve symbol : Symbol : 14.00 Timer Location : 14.00 JCTX Time = new Timer (10, this);            ^ 9 errors Process completed. Sorry Sorry, forget the above packages into related Import javax.swing.*; Import java.awt.*; You will be able to add these two sentences Sorry Ok, i solved it. By adding two line : Import javax.swing.*; Import java.awt.*; [ Closed window ]