App stopped working due to database

Iam creating a signup page, when I enter different passwords, toast is working just fine. But when i enter same passwords. Page is not being redirected to a new page. It just crashes with a message "app stopped working" and im redirected to my main activity again.

package com.example.abcd.helloworld;
import....

public class SignUp extends Activity {
DatabaseHelper helper = new DatabaseHelper(this);

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.signup);
    Button button2 = (Button) findViewById(R.id.Bsignupbutton);

    button2.setOnClickListener(new View.OnClickListener() {

        @Override

        public void onClick(View v) {
            if (v.getId() == R.id.Bsignupbutton) {
                EditText name = (EditText) findViewById(R.id.TFname);
                EditText email = (EditText) findViewById(R.id.email);
                EditText uname = (EditText) findViewById(R.id.TFuname);
                EditText pass1 = (EditText) findViewById(R.id.password);
                EditText pass2 = (EditText) findViewById(R.id.pass2);

                String namestr = name.getText().toString();
                String emailstr = email.getText().toString();
                String unamestr = uname.getText().toString();
                String pass1str = pass1.getText().toString();
                String pass2str = pass2.getText().toString();
                if (!pass1str.equals(pass2str)) {
                    //popup msg
                    Toast pass = Toast.makeText(SignUp.this, "Passwords do not match!", Toast.LENGTH_SHORT);
                    pass.show();
                } else {
                    User u = new User();
                    u.setName(namestr);
                    u.setEmail(emailstr);
                    u.setUname(unamestr);
                    u.setPass(pass1str);

                    helper.insertUser(u);
                    Intent i = new Intent(SignUp.this, yaya.class);
                    startActivity(i);
                }

            }
        }
    });
}

}