Simple Java Program Error

I am writing a simple java program using Netbeans 5.0 Beta 2 and I keep on getting an error and the program is straight from the book. Her is the program.



public class ComputeArea
{
/**Main method*/
public static void main(String[] args)
{
double radius;
double area;

// Prompt the user to enter radius
System.out.print("Enter radius: ");
radius = MyInput.readDouble();

// Compute area
area = radius*radius*3.14159;

// Display results
System.out.println("The area for the circle of radius " +
radius + " is " + area);
}
}
I keep on getting an error at the radius=MyInput.readDouble();

It says that it cannot find symbol
symbol: variable MyInput
location: class Computearea.Main

 

The variable "MyInput" is probably named something else... this is a common problem one encounters when copying program examples from other sources; it's difficult to remember to substitute your names for the author's ;-)

Most likely, you have named the text field or area you are using to get user data something other than "MyInput" and you therefore need to change your code to reflect this.

It's a good hint that when an author creates a code example that includes variable names like MyThis or MyThat, you are supposed to substitute the appropriate variable names you are using in the program.

I hope this helps.