different layout with spinner - android-layout

Question

I want to show a different layout when a user selects series2 from spinner and a different one when he selects other items from spinner.
How can it be done?
This is my code:
public class MainActivity extends Activity {
Button button;
EditText editText
EditText editText2;
TextView textView, textView3;
int num1;
int num2;
int j = 0;
int s;
int c;
Spinner spinner,spinner1;
String spinner_name_data;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id.textView);
editText = (EditText) findViewById(R.id.editText);
editText2 = (EditText) findViewById(R.id.editText2);
button = (Button) findViewById(R.id.button);
textView3 = (TextView) findViewById(R.id.textView3);
spinner = (Spinner) findViewById(R.id.spinner1);
final String[] test = new String[]{"series1", "series2", "series3"};
ArrayAdapter<String> gameKindArray = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_spinner_item, test);
gameKindArray.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(gameKindArray);
spinner.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> arg0, View arg1, int index, long arg3) {
spinner_name_data = spinner.getSelectedItem().toString();
if (spinner_name_data.equals(test[0]))
{
textView3.setText(Html.fromHtml("1+x<sup><small>2</small></sup>+x<sup><small>3</small></sup>+x<sup><small>4</small></sup>+x<sup><small>5</small></sup>+.........+x<sup><small>n</small></sup>"));
} else if (spinner_name_data.equals(test[1]))
{
setContentView(R.layout.layout2);
textView = (TextView) findViewById(R.id.textView);
editText = (EditText) findViewById(R.id.editText);
editText2 = (EditText) findViewById(R.id.editText2);
button = (Button) findViewById(R.id.button);
textView3 = (TextView) findViewById(R.id.textView3);
spinner1 = (Spinner) findViewById(R.id.spinner1);
final String[] test = new String[]{"series1", "series2", "series3"};
ArrayAdapter<String> gameKindArray = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_spinner_item, test);
gameKindArray.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(gameKindArray);
textView3.setText(Html.fromHtml("0+1+1+2+3+5+8+....n times"));
} else {
textView3.setText(Html.fromHtml("1+1/x+x<sup><small>2</small></sup>+1/x<sup><small>3</small></sup>+x<sup><small>4</small></sup>+1/x<sup><small>5</small></sup>+.....+x<sup><small>n</small></sup>"));
}
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
button.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v) {
spinner_name_data = spinner.getSelectedItem().toString();
if (spinner_name_data.equals(test[0])) {
String strNum1 = editText.getText().toString().trim();
String strNum2 = editText2.getText().toString().trim();
if (strNum1.length() == 0) {
Toast.makeText(MainActivity.this, "Please enter X", Toast.LENGTH_SHORT).show();
return;
}
if (strNum2.length() == 0) {
Toast.makeText(MainActivity.this, "Please enter N", Toast.LENGTH_SHORT).show();
return;
}
num1 = Integer.parseInt(strNum1);
num2 = Integer.parseInt(strNum2);
int c = 1, t1, t2 = 0;
for (int i = 1; i < num1; i++) {
int t = c;
c = c * num2;
t1 = t + c;
t2 = t1 + t2;
}
j = t2 + c + 1;
j = j / 2;
textView.setText(String.valueOf(j));
}else if (spinner_name_data.equals(test[1])){
String strNum1 = editText.getText().toString().trim();
if (strNum1.length() == 0) {
Toast.makeText(MainActivity.this, "Please enter n", Toast.LENGTH_SHORT).show();
return;
}
num1 = Integer.parseInt(strNum1);
int a=0,b=1;
for(int i=1;i<num1;i++){
c=a+b;
a=b;
b=c;
}
textView.setText(String.valueOf(c));
}else{
String strNum1 = editText.getText().toString().trim();
String strNum2 = editText2.getText().toString().trim();
if (strNum1.length() == 0) {
Toast.makeText(MainActivity.this, "Please enter X", Toast.LENGTH_SHORT).show();
return;
}
if (strNum2.length() == 0) {
Toast.makeText(MainActivity.this, "Please enter N", Toast.LENGTH_SHORT).show();
return;
}
}
}
});
}
}