public void 온클릭(View v){
switch(v.getId()){
case R.id.registerDB :
memberDB = myHelper.getWritableDatabase();
 if(memberDB.isOpen()){
memberDB.execSQL("INSERT INTO memberTBL VALUES('" + edtId.getText().toString() +        //NullPointerException 에러 발생
"', '" + edtPw.getText().toString() + "', '" + edtName.getText().toString() +
"', '" + edtBirth.getText().toString() + "', '" + edtAdd.getText().toString() +
"', '" + edtPhone.getText().toString() + "', '" + edtMphone.getText().toString() +
"', '" + edtEmail.getText().toString() + "');");
 memberDB.close();
 Toast.makeText(this, "등록되었습니다", Toast.LENGTH_SHORT).show();
 break;
 }
else Toast.makeText(this, "DB 등록 오류!", Toast.LENGTH_SHORT).show();
 case R.id.cancel_register :
finish(); break;
 }
}

이런경우엔 어떤부분을 살펴봐야 하나요