java - Cannot refer to a variable inside an inner class -

i'm still learning java bear me. trying write program click button named "yes" , increases variable y 1, , same button "no" on variable x. i'm using eclipse , windowbuilder pro , gives me error "cannot refer variable inside inner class"

here's code:

    import javax.swing.japplet;     import javax.swing.jbutton;     import java.awt.event.mouseadapter;     import java.awt.event.mouseevent;     import javax.swing.jformattedtextfield;       public class qa extends japplet {          /**          * create applet.          */         public qa() {             getcontentpane().setlayout(null);              int y=0;             int x=0;             string s1 = string.valueof(y);               jbutton btnyes = new jbutton("yes");             btnyes.addmouselistener(new mouseadapter() {                 @override                 public void mouseclicked(mouseevent arg0) {                     ++y;                 }             });             btnyes.setbounds(135, 220, 85, 42);             getcontentpane().add(btnyes);              jbutton btnno = new jbutton("no");             btnno.addmouselistener(new mouseadapter() {                 @override                 public void mouseclicked(mouseevent e) {                     ++x;                 }             });             btnno.setbounds(230, 220, 85, 42);             getcontentpane().add(btnno);              jformattedtextfield frmtdtxtfldvarible = new jformattedtextfield();             frmtdtxtfldvarible.settext(s1);             frmtdtxtfldvarible.setbounds(147, 130, 157, 20);             getcontentpane().add(frmtdtxtfldvarible);           }     } 

thanks help!

declare x , y instance variables don't need declare them final local variables:

public class qa extends japplet {     private int x = 0;     private int y = 0;      // ... }