Area and volume of cylinder

[melissax]

C++3.jpg
When i select option 1 there is no problem but when i enter double program sending volume value.
C++4.jpg
Which part i have to make changes.

cout<<"\nEnter radius of Cylinder\n";
	cin>>r;
	cout<<"\nEnter height of Cylinder\n";
	cin>>h;
 	switch(ch)
 	{       
                case 1:
			obj.cylinder_area(r,h);
			break;
		case 2:
			obj.cylinder_volume(r,h);
			break;
		default:
			cout<<"\nThe choice entered is a wrong choice";
	}

This isnt work in my program.