MonthlyPaycheckCalculator using user-defined methods

[Roy1287]

Hey. I've been working on this for a while and am having a lot of trouble with it. What I have to do is:

Some processing requirements:
- all data entry will be in the main method
- must use a sentinel loop to stop processing salespersons
- must test for valid data and if not correct, must keep prompting until the user enters in valid data
- create user-defined methods for the following:
* isNumeric: this method will determine if the string passed in is numeric. The method will return a TRUE value if the string is numeric and FALSE if the string is not numeric
* calcBonus: this method will calculate the saleperson's bonus based on the above table. This method will calculate the bonus and return this value.
* calcCommission: this method will calculate the commission the salesperson earned and return this value.
- the output will be generated from the main method
- The output generated will include:
The Salesperon’s name and paycheck amount

This is my first time using user defined methods and am struggling a lot.
So far i have this as the main body of the program:

import java.io.*;
import java.util.*;

public class MonthlyPaycheckCalculator
{
	//scanner
	static Scanner console = new Scanner(System.in);
	public static void main(String[]args)
	{
		//local variables
		String salespersonName;
		double baseSalary;
		int yearsOfService;
		double totalSales;
		double bonus;
		double additionalBonus;

//Get salespersonName
System.out.print("Please Enter Name of Salesperson (Enter # to end entry)");
System.out.println();
salespersonName = console.next();
System.out.println();

while (salespersonName != "#");
//Get baseSalary
System.out.print("Please Enter Base Salary");
System.out.println();
baseSalary = console.nextDouble();
System.out.println();
//check isNumeric

//Get yearsOfService
System.out.print("Please Enter Years of Service");
System.out.println();
yearsOfService = console.nextInt();
System.out.println();
//check isNumeric

//Get totalSales
System.out.print("Enter Sale Total");
System.out.println();
totalSales = console.nextDouble();
System.out.println();
	}
}

This is my isNumeric method:

public class isNumeric
{
    // This method checks if a String contains only numbers
    public boolean isNumeric(String str)
    {
        //It can't contain only numbers if it's null or empty
        if (str == null || str.length() == 0)
            return false;
        for (int i = 0; i < str.length(); i++)
        {
            //non-digit character returns false.
            if (!Character.isDigit(str.charAt(i)))
                return false;
        }
        return true;
    }
}

This is my calcBonus method:

public class calcBonus
{
// constants
    private static final double ltfYears = 10.00; // less than five years bonus
    private static final double mtfYears = 20.00; // more than five years bonus
    private static final int bonusStep = 5;
// main
    {
    // Local variables
        int yearsWorked; //reads in years as string
        double bonus;		//calculated bonus

        if (yearsWorked <= bonusStep)
        //... Computation
        bonus = ltfYears * yearsWorked;                                      //Note 1
        else
        bonus = mtfYears * yearsWorked;
        //... Output
        System.out.printf("Bonus: $%.2f", bonus);
        System.out.println();
    }
}

And I have not done anything with the calcCommission method yet.

Can someone tell me whether either of my methods are on the right track, or if not what I need to do differently, and for the main body, is it set up right or am I way off on that as well?

This is all done in Java btw. Any help would be greatly appreciated. Thanks.