Cant able to open datepicker

[lakkad-amish]

Hello
I am trying to open a dialog from the activity but it crashed everytime.please help.

i have initiated like this

public class TaskStatus extends FragmentActivity implements OnClickListener,OnDateSetListener{
{
calendar = Calendar.getInstance();
datePickerDialog = DatePickerDialog.newInstance(TaskStatus.this, calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH), calendar.get(Calendar.DAY_OF_MONTH), true);

and on click event i have written code as below

datePickerDialog.setVibrate(true);
datePickerDialog.setYearRange(1985, 2028);
datePickerDialog.setCloseOnSingleTapDay(true);
datePickerDialog.show(getSupportFragmentManager(), "datepicker");