Why is my code crashing when button is pressed?

I am using android studio and when I click the button the program crashes. The if statements don't seem to be working. Please could you help. import android.content.Intent; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast;

public class customerDetails extends AppCompatActivity {
    EditText NameEditText, editTextPhoneNumber, postcodeEditText;
    Button Continue;
    String Name, postcode, PhoneNumber;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.content_customer_details);

        Continue = (Button) findViewById(R.id.Continue);
        NameEditText = (EditText) findViewById(R.id.NameEditText);
        postcodeEditText = (EditText) findViewById(R.id.postcodeEditText);
        final String strFromActivity = getIntent().getStringExtra("MY_INFO");

        Continue.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Name = NameEditText.getText().toString();
                postcode = postcodeEditText.getText().toString();
                PhoneNumber = editTextPhoneNumber.getText().toString();


                if (Name.length() == 0 || !(Name.matches("[a-zA-Z]"))) {
                    NameEditText.requestFocus();
                    NameEditText.setError("FIELD CANNOT BE EMPTY AND ONLY HAVE ALPABETICAL CHARACTERS");
                }
                else if (postcode.length() == 0 || !(postcode.matches("[a-zA-Z1-9]+"))) {
                    postcodeEditText.requestFocus();
                    postcodeEditText.setError("FIELD CANNOT BE EMPTY AND ENTER ONLY ALPHABETICAL CHARACTER OR NUMBER");
                }
                else if (PhoneNumber.length() == 0 || (!(PhoneNumber.matches("[^[0-9]*$]+")))) {
                    editTextPhoneNumber.requestFocus();
                    editTextPhoneNumber.setError("FIELD CANNOT BE EMPTY");
                }
                else {

                    Intent emailIntent = new Intent(Intent.ACTION_SEND);
                    emailIntent.setType("message/rfc822");
                    emailIntent.putExtra(Intent.EXTRA_EMAIL, new String[]{"woodensigns414@gmail.com"});
                    emailIntent.putExtra(Intent.EXTRA_SUBJECT, "Order");
                    emailIntent.putExtra(Intent.EXTRA_TEXT, "Product" + strFromActivity + "Customer Name" + NameEditText);
                    Toast.makeText(getApplicationContext(), "Order Complete", Toast.LENGTH_SHORT).show();
                    try {
                        startActivity(Intent.createChooser(emailIntent, "Send Details..."));
                        finish();
                    } catch (android.content.ActivityNotFoundException ex) {
                        Toast.makeText(customerDetails.this, "There is no email client installed.", Toast.LENGTH_SHORT).show();
                    }
                    Intent intent2 = new Intent(customerDetails.this, OrderComplete.class);
                    startActivity(intent2);


                }
            }

        });
    }
}