مشکل این کد چیه؟

سلام. من اون پروژه تبدیل واحد رو درست کردم خودم اما نمیدونم چرا هر وقت دکمه Calculate رو میزنم عدد تغییر میکنه. نه که تغییر کنه. اول بار درسته اما بعدش یه صفر اضافه میشه جلوش و بقیه اعداد هم یه صفر میگیرند. هر چی به کدش نگاه کردم که مشکلش چیه متوجه نشدم. ممنون میشم شما کمک کنید.

package com.sajad.converter;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnFocusChangeListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;


public class VelocityActivity extends Activity {

    public EditText edtCmS;
    public EditText edtMmS;
    public EditText edtKmS;
    public EditText edtMS;
    public EditText UserInput;
    public Button   btnCalculate;

    double          MS  = 0;
    double          KmS = 0;
    double          CmS = 0;
    double          MmS = 0;


    @Override
    protected void onCreate(Bundle savedInstanceState) {

        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.velocity);

        edtCmS = (EditText) findViewById(R.id.edtCmS);
        edtMmS = (EditText) findViewById(R.id.edtMmS);
        edtKmS = (EditText) findViewById(R.id.edtKmS);
        edtMS = (EditText) findViewById(R.id.edtMS);
        btnCalculate = (Button) findViewById(R.id.btnCalculate);

        FocusChanged();

        OnClickListener btnCalculateClicked = (new OnClickListener() {

            @Override
            public void onClick(View view) {

                if (edtMS.getText().toString().length() > 0) {
                    //MS = Double.parseDouble(edtMS.getText().toString());
                    KmS = Double.parseDouble(edtMS.getText().toString()) * 0.001;
                    CmS = Double.parseDouble(edtMS.getText().toString()) * 100;
                    MmS = Double.parseDouble(edtMS.getText().toString()) * 1000;
                    edtKmS.setText("" + KmS);
                    edtMmS.setText("" + MmS);
                    edtCmS.setText("" + CmS);
                    return;

                }

                if (edtKmS.getText().toString().length() > 0) {
                    //KmS = Double.parseDouble(edtKmS.getText().toString());
                    MS = Double.parseDouble(edtKmS.getText().toString()) * 1000;
                    CmS = Double.parseDouble(edtKmS.getText().toString()) * 10000;
                    MmS = Double.parseDouble(edtKmS.getText().toString()) * 1000000;
                    edtMmS.setText("" + MmS);
                    edtMS.setText("" + MS);
                    edtCmS.setText("" + CmS);
                    return;
                }
                if (edtCmS.getText().toString().length() > 0) {
                    //CmS = Integer.parseInt((edtCmS.getText().toString()));
                    MS = Double.parseDouble(edtCmS.getText().toString()) * 0.01;
                    KmS = Double.parseDouble(edtCmS.getText().toString()) * 0.00001;
                    MmS = Double.parseDouble(edtCmS.getText().toString()) * 10;
                    /*
                                        BigDecimal KMS = new BigDecimal(Double.toString(KmS));
                                        BigDecimal MMS = new BigDecimal(Double.toString(MmS));
                                        BigDecimal MS1 = new BigDecimal(Double.toString(MS));
                    */
                    edtKmS.setText("" + KmS);
                    edtMmS.setText("" + MmS);
                    edtMS.setText("" + MS);
                    return;
                }
                if (edtMmS.getText().toString().length() > 0) {
                    //MmS = Double.parseDouble(edtMmS.getText().toString());
                    MS = Double.parseDouble(edtMmS.getText().toString()) * 0.001;
                    KmS = Double.parseDouble(edtMmS.getText().toString()) * 0.000001;
                    CmS = Double.parseDouble(edtMmS.getText().toString()) * 0.1;
                    edtKmS.setText("" + KmS);
                    edtMS.setText("" + MS);
                    edtCmS.setText("" + CmS);
                    return;
                }

            }
        });

        btnCalculate.setOnClickListener(btnCalculateClicked);

    }


    public void FocusChanged() {

        OnFocusChangeListener FocusChange = (new OnFocusChangeListener() {

            @Override
            public void onFocusChange(View view, boolean arg1) {
                switch (view.getId()) {
                    case R.id.edtMS:
                        Toast.makeText(VelocityActivity.this, "edtCmS Clicked", Toast.LENGTH_SHORT).show();
                        edtMS.setText("");
                        edtMmS.setText("");
                        edtKmS.setText("");

                        break;
                    case R.id.edtCmS:
                        Toast.makeText(VelocityActivity.this, "edtCmS Clicked", Toast.LENGTH_SHORT).show();
                        edtMS.setText("");
                        edtMmS.setText("");
                        edtKmS.setText("");
                        break;
                    case R.id.edtKmS:
                        Toast.makeText(VelocityActivity.this, "edtKmS Clicked", Toast.LENGTH_SHORT).show();
                        edtMS.setText("");
                        edtCmS.setText("");
                        edtMmS.setText("");
                        break;
                    case R.id.edtMmS:
                        Toast.makeText(VelocityActivity.this, "edtMS Clicked", Toast.LENGTH_SHORT).show();
                        edtKmS.setText("");
                        edtCmS.setText("");
                        edtMmS.setText("");
                        break;
                }

            }
        });
        edtKmS.setOnFocusChangeListener(FocusChange);
        edtCmS.setOnFocusChangeListener(FocusChange);
        edtMmS.setOnFocusChangeListener(FocusChange);
        edtMS.setOnFocusChangeListener(FocusChange);

    }
}