Button btnToast = (Button) findViewById(R.id.btnToast);
        btnToast.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v){
                EditText txtNama = (EditText)findViewById(R.id.txtNama);


                String nama  = txtNama.getText().toString();
                Toast.makeText(getApplicationContext(),"Halo " + nama + "...", Toast.LENGTH_SHORT).show();

            }
        });