Thread: someone help

Hey everybody im really bad at programming can someone proofread this code and make the necessary corrections? i tried to do it myself and it never compiled. the code is for a dialog box that calculates the volume of a cylinder, and i know there are simpler codes to do it, but this is the format my teacher wants
Heres the code:

    import javax.swing.*;
    public class classTwo
    {
        public static void main(String[] args)
        {
            String rad, hei, vol;
            Scanner joe = new Scanner(System.in);
            System.out.println ("Hi, please enter a radius.");
            double rad = joe.nextLine();
            System.out.println ("Enter a height.");
            double hei = joe.nextLine();
            vol = 3.14 * rad * rad * hei;
            System.out.println ("The volume of your cylinder is" + vol + ".");
        } 
    }

P.S. im using BlueJ, if that is relevant

Sorry, we don't do students work for them. We will help you get the code to work.

If there are errors, copy the full text of the error messages and paste it here.

variable rad is already defined

You can only define a variable one time in the existing scope.
You can reuse an existing variable as often as you want
or you can change the name of the variable so it's different from the name of an existing variable.