swing - ActionListener Problems in Java -

i have been trying fix code few hours , still can't rid of error. in code below, one.addactionlistener(this) , two.addactionlistener(this) both have red lines under this saying 'cannot use in static context'. please me out if can. thanks!

    import java.awt.event.actionevent;     import java.awt.event.actionlistener;     import java.awt.event.windowevent;     import java.awt.event.windowlistener;         import javax.swing.jbutton;     import javax.swing.jframe;      public class themain extends jframe implements actionlistener, windowlistener {          int input1 = 0;         int input2 = 0;          public static void main(string[] args) {             themain main = new themain();             jbutton 1 = new jbutton("1");             one.setsize(10, 10);             one.addactionlistener(this);                 jbutton 2 = new jbutton("2");             two.setsize(10, 10);             two.addactionlistener(this);         }      public themain(){     jbutton 1 = new jbutton("1");     one.setsize(10, 10);     one.addactionlistener(this);                  jbutton 2 = new jbutton("2");     two.setsize(10, 10);     two.addactionlistener(this);              jframe frame = new jframe("window");     frame.setsize(200, 250);     frame.setvisible(true);     frame.add(one);     frame.add(two);     }      public void actionperformed(actionevent e) {         if(input1 != 0){             if(input2 != 0){                 system.out.println("max 2 numbers!");             }else{                 input2 = 1;             }         }else{             input1 = 1;         }                }      public void actionperformed1(actionevent e) {         if(input1 != 0){             if(input2 != 0){                 system.out.println("max 2 numbers!");             }else{                 input2 = 2;             }         }else{             input1 = 2;         }                }      @override     public void windowopened(windowevent e) {         // todo auto-generated method stub         }      @override     public void windowclosing(windowevent e) {         // todo auto-generated method stub         }      @override     public void windowclosed(windowevent e) {         // todo auto-generated method stub         }      @override     public void windowiconified(windowevent e) {         // todo auto-generated method stub         }      @override     public void windowdeiconified(windowevent e) {         // todo auto-generated method stub         }      @override     public void windowactivated(windowevent e) {         // todo auto-generated method stub         }      @override     public void windowdeactivated(windowevent e) {         // todo auto-generated method stub         }     } 

within static method can use static variables or local variables, can't use instance variables, , this represents themain instance, can't use in main method, static. should change

addactionlistener(this); 

to

addactionlistener(main);