swing - UImanager look and feel partially working/ Java programming -

i wanted change graphics of default jframe using uimanager.

uimanager.setlookandfeel("javax.swing.plaf.nimbus.nimbuslookandfeel"); 

this works on main frame if call panel, doesn't.

ex: (i have use this)

joptionpane.showmessagedialog(this, new mypanel, "about", joptionpane.plaintext); 

i tried putting ui manager in jpanel, comes default ugly interface. suggestions?

update:

here example frame:

import java.awt.borderlayout; import java.awt.eventqueue;  import javax.swing.borderfactory; import javax.swing.jframe; import javax.swing.joptionpane; import javax.swing.jpanel; import javax.swing.uimanager; import javax.swing.unsupportedlookandfeelexception; import javax.swing.border.emptyborder; import javax.swing.jmenubar; import javax.swing.jmenu; import java.awt.gridlayout; import javax.swing.swingconstants; import java.awt.component; import javax.swing.box; import javax.swing.jslider; import java.awt.gridbaglayout; import java.awt.gridbagconstraints; import javax.swing.jlabel; import java.awt.insets; import javax.swing.jprogressbar; import java.awt.flowlayout; import javax.swing.jbutton;  import java.awt.headlessexception; import java.awt.panel; import java.awt.label; import java.awt.dimension; import java.awt.font; import java.awt.toolkit;  import javax.swing.jmenuitem; import java.awt.event.actionlistener; import java.awt.event.actionevent;  public class musicplayerframe extends jframe {      private jpanel contentpane;     private static musicplayerframe frame;     private static musicplayerabout about;      /**      * launch application.      */     public static void main(string[] args) {         eventqueue.invokelater(new runnable() {             public void run() {                 try {                     frame = new musicplayerframe();                     frame.setvisible(true);                 } catch (exception e) {                     e.printstacktrace();                 }                 try {                     uimanager                             .setlookandfeel("javax.swing.plaf.nimbus.nimbuslookandfeel");                 } catch (classnotfoundexception e) {                     // todo auto-generated catch block                     e.printstacktrace();                 } catch (instantiationexception e) {                     // todo auto-generated catch block                     e.printstacktrace();                 } catch (illegalaccessexception e) {                     // todo auto-generated catch block                     e.printstacktrace();                 } catch (unsupportedlookandfeelexception e) {                     // todo auto-generated catch block                     e.printstacktrace();                 }                 = new musicplayerabout();             }         });     }      /**      * create frame.      */     public musicplayerframe() {         setdefaultcloseoperation(jframe.exit_on_close);         int width = 450;         int height = 300;         dimension screensize = toolkit.getdefaulttoolkit().getscreensize();          setbounds((screensize.width - width) / 2,                 (screensize.height - height) / 2, 721, 507);          jmenubar menubar = new jmenubar();         setjmenubar(menubar);          jmenu mnfile = new jmenu("file");         menubar.add(mnfile);          jmenuitem mntmexit = new jmenuitem("exit");         mntmexit.addactionlistener(new actionlistener() {             public void actionperformed(actionevent e) {                 system.exit(0);             }         });         mnfile.add(mntmexit);          jmenu mnhelp = new jmenu("help");         menubar.add(mnhelp);          jmenuitem mntmabout = new jmenuitem("about");         mntmabout.addactionlistener(new actionlistener() {             public void actionperformed(actionevent e) {                 joptionpane.showmessagedialog(frame, about, "about",                         joptionpane.plain_message);              }         });         mnhelp.add(mntmabout);         contentpane = new jpanel();         contentpane.setborder(new emptyborder(5, 5, 5, 5));         contentpane.setlayout(new borderlayout(0, 0));         setcontentpane(contentpane);          jpanel genrepanel = new jpanel();         genrepanel.setborder(borderfactory.createtitledborder("genre"));         contentpane.add(genrepanel, borderlayout.north);         genrepanel.setlayout(new gridlayout(1, 0, 0, 0));          jpanel songpanel = new jpanel();         songpanel.setborder(borderfactory.createtitledborder("songs"));         contentpane.add(songpanel, borderlayout.center);         songpanel.setlayout(new gridlayout(1, 0, 0, 0));          jpanel controlspanel = new jpanel();         contentpane.add(controlspanel, borderlayout.south);         controlspanel.setlayout(new borderlayout(0, 0));          jpanel panel_3 = new jpanel();         controlspanel.add(panel_3, borderlayout.north);          jprogressbar progressbar = new jprogressbar();         panel_3.add(progressbar);          jpanel panel_5 = new jpanel();         controlspanel.add(panel_5, borderlayout.center);          jlabel lblnewlabel = new jlabel("0");         lblnewlabel.setfont(new font("tahoma", font.plain, 18));         panel_5.add(lblnewlabel);          jslider slider = new jslider();         panel_5.add(slider);          label label = new label(")))");         label.setfont(new font("tahoma", font.plain, 18));         panel_5.add(label);         label.setalignment(label.center);          jpanel panel_4 = new jpanel();         controlspanel.add(panel_4, borderlayout.south);          jbutton btnyj = new jbutton("yj");         panel_4.add(btnyj);     }  } 

and panel calls:

import javax.swing.jpanel; import javax.swing.uimanager; import javax.swing.unsupportedlookandfeelexception;  import java.awt.gridbaglayout; import java.awt.gridbagconstraints; import java.awt.insets; import javax.swing.jlabel; import javax.swing.border.etchedborder; import java.awt.font;  public class musicplayerabout extends jpanel {      public musicplayerabout() {          gridbaglayout gridbaglayout = new gridbaglayout();         gridbaglayout.columnwidths = new int[]{0, 0};         gridbaglayout.rowheights = new int[]{0, 0, 0, 0, 0};         gridbaglayout.columnweights = new double[]{1.0, double.min_value};         gridbaglayout.rowweights = new double[]{0.0, 1.0, 0.0, 0.0, double.min_value};         setlayout(gridbaglayout);          jpanel panel = new jpanel();         panel.setborder(new etchedborder(etchedborder.lowered, null, null));         gridbagconstraints gbc_panel = new gridbagconstraints();         gbc_panel.insets = new insets(0, 0, 5, 0);         gbc_panel.fill = gridbagconstraints.both;         gbc_panel.gridx = 0;         gbc_panel.gridy = 1;         add(panel, gbc_panel);         gridbaglayout gbl_panel = new gridbaglayout();         gbl_panel.columnwidths = new int[]{0, 0};         gbl_panel.rowheights = new int[]{0, 0, 0, 0, 0, 0};         gbl_panel.columnweights = new double[]{1.0, double.min_value};         gbl_panel.rowweights = new double[]{0.0, 0.0, 0.0, 0.0, 0.0, double.min_value};         panel.setlayout(gbl_panel);            jlabel lblapril = new jlabel("april, 2013");         gridbagconstraints gbc_lblapril = new gridbagconstraints();         gbc_lblapril.insets = new insets(0, 0, 5, 0);         gbc_lblapril.gridx = 0;         gbc_lblapril.gridy = 2;         panel.add(lblapril, gbc_lblapril);         lblapril.setfont(new font("tahoma", font.bold, 17));          try {             uimanager             .setlookandfeel("javax.swing.plaf.nimbus.nimbuslookandfeel");         } catch (classnotfoundexception e) {             // todo auto-generated catch block             e.printstacktrace();         } catch (instantiationexception e) {             // todo auto-generated catch block             e.printstacktrace();         } catch (illegalaccessexception e) {             // todo auto-generated catch block             e.printstacktrace();         } catch (unsupportedlookandfeelexception e) {             // todo auto-generated catch block             e.printstacktrace();         }     }  } 

if run panel itself, works if call other frame, doesn't seem to.

any appreciated!