java - TextArea not responsing -

i have tried setting text in textarea while clicking on button, no text shows up. can do?

i want find prime numbers number textfield, textarea not responding?

package primnum;  import java.awt.borderlayout; import java.awt.dimension; import java.awt.flowlayout; import java.awt.font; import java.awt.gridlayout; import java.awt.scrollpane; import java.awt.event.actionevent; import java.awt.event.actionlistener; import javax.swing.*;  public class pframe extends jframe { private jlabel l1,l2, l3; private jtextfield f1 ; private jbutton b; private jtextarea t; private jpanel p ,p1,p2; private string s, s2, s3; private int m ; private font f;  public pframe(){         super("prime numbers");         //setlayout(new gridlayout(3,1));         s = new string("enter number (n)");         f = new font("sansarif" , font.bold,14);         l1 = new jlabel(s);         l3=new jlabel("           ");         l1.setfont(f);         p = new jpanel();         p.setlayout(new flowlayout());         p.add(l1);         f1 = new jtextfield(20);         p.add(f1);         add(p,borderlayout.north);         p1 = new jpanel();         p1.setlayout(new gridlayout(4,1));         b = new jbutton("find primes");         b.setsize(1, 3);         p1.add(l3);         p1.add(b);         add(p1,borderlayout.center);         l2 = new jlabel("           list of prime numbers less n");         l2.setfont(f);         p2 =new jpanel();         t = new jtextarea(null,20,60);         t.seteditable(false);         p2.add(l2,borderlayout.north);         p2.add(new jscrollpane(t),borderlayout.south);         add(p2,borderlayout.south);         b.addactionlistener(new actionlistener(){             @override             public void actionperformed(actionevent e) {                if(f1 == null)                  joptionpane.showmessagedialog(null, "unvalid number","",joptionpane.error_message);                else{                    s2 = f1.gettext();                    m = integer.parseint(s2);                    for(int = 2 ; i<= m ;i++ ){                      (int j=2; j<=i;j++){                        if(j==i){                          t.append(""+i+"\n");//display prime numbers in textarea                        }                        if(i%j==0)                          break;                        }                    }                   }              }           });       }   }