Solution Review: Design an ATM

class ATMmachine
{
    public static void main (String args[])
    {
        ATM obj = new ATM("0-2281291291-21", "29wjsw2", 249000);
        // Withdrawing the money
        System.out.println( obj.withdrawal("29wjsw2", "34000"));
    }
}
class ATM   // Header of the class
{
    //Private fields
    private String accNo;
    private String accPassword;
    private double balance;
    // The parameterized constructor
    public ATM(String AccNo, String Password, double Balance) 
    {
        accNo = AccNo;
        accPassword = Password;
        balance = Balance;
    }
    // Write your function withdrawal here
    public String withdrawal(String password, String cash) 
    {
        if (accPassword.equals(password))                  // First checking the passowrd
        {   
            /* Step 1: If cash is null; no further checks and return error message
               Step 2: If cash doesn't have all numbers; no further checks and return error message
               Step 3: If cash is greater than balance; no further checks and return error message
               Step 4: If cash is greater than 50,000; return error message
            */
            if (cash != null && cash.matches("[-+]?\\d*\\.?\\d+") && Double.parseDouble(cash) <= this.balance && Double.parseDouble(cash) <= 50000) 
            {
                balance -= Double.parseDouble(cash);    // Deducting balance
                return "Withdrawal is successful. Your current balance is $" + balance;
            }
            else    // error message
            {  
                return "Please enter the correct amount.";
            }
        }
        else       // If password wasn't correct
        {  
            return "Wrong Password!";
        }
    }     
}