insert data to database throug textfield in java

import java.awt.*;
import java.awt.event.*;
import java.sql.*;
public class fdemo extends Frame implements ActionListener
{
Label l1,l2;
TextField t1,t2;
Button b1,b2;
public fdemo()
{
t1=new TextField(10);
t1.setVisible(true);
t2=new TextField(10);
l1=new Label("name");
l2=new Label("id");
l1.setBounds(10,10,20,20);
l2=new Label("age");
b1=new Button("Exit");
b2=new Button("insert");
add(l1);
add(t1);
add(l2);
add(t2);
add(t2);
add(b1);
add(b2);
setLayout( new FlowLayout());
b1.addActionListener(this);
b2.addActionListener(this);
}
public void add_()
{
try
{
//'"s1"'
Class.forName("com.mysql.jdbc.Driver");
      Connection c=DriverManager.getConnection("jdbc:mysql://localhost/rocks","root","");
      Statement s=c.createStatement();
s.executeUpdate("insert into _data values("+t1.getText()+")");

}
catch(Throwable t)
{
System.out.println(t);
}
System.out.println("executed");
}
public void actionPerformed(ActionEvent e)
{
String s=e.getActionCommand();
switch(s)
{
case "Exit":
System.exit(0);
break;
case "insert":
add_();
break;
}

}

public static void main( String s[])
{
fdemo f=new fdemo();
f.setVisible(true);
f.setSize(200,200);
}
}