Return statement error and java.lang.noclassDefFoundError?

Question

public class Calculation
     public static void main (String[] args)
          int a[]=new int [12];
          int iNum=0;
          MainPrompt();
     static public int MyInput()
     return MyInput.readInt();
     public static boolean MainPrompt()
          System.out.println("\n This program will show you the times table [1-12] of any number between 1 & 100 inclusive.");
          int a[]=new int [12];
          int iNum = 0;
          do
               do
                    System.out.print("\n Enter your number [1-100] or 999 to exit: ");
                    iNum = MyInput();
                    while ((iNum>=1)&&(iNum<=100));
                         if (iNum==999)
                              System.out.println("\n Goodbye \n");
                    while (!(((iNum>=1)&&(iNum<=100))||(iNum==999)));
                         if ((iNum>=1)&&(iNum<=100))
                              Calculation(a,iNum);
                              TimesTable(a,iNum);
     public static void Calculation(int a[], int iNum)
          for(int j=0;j<a.length;j++)
          a[j]=iNum*(j+1);
     public static void TimesTable(int a[], int iNum)
          for(int i=0;i<a.length;i++)
          System.out.println((i+1)+"     *"+iNum+"     ="+a);
In build output it says missing return statement line 42 "}"
and also when I try to execute the program it gives me the Exception in thread "main" java.lang.NoClassDefFoundError: calculation
In the folder I have placed the myinput.java and myinput.class file where my calculation.java is, but still no go.
can anyone here help me out here?
thanks in advance

Answer 1

public class Calculation
     public static void main (String[] args)
          int a[]=new int [12];
          int iNum=0;
          MainPrompt();
     static public int MyInput()
     return MyInput.readInt();
     public static void MainPrompt()
          System.out.println("\n This program will show you the times table [1-12] of any number between 1 & 100 inclusive.");
          int a[]=new int [12];
          int iNum = 0;
          do
               do
                    System.out.print("\n Enter your number [1-100] or 999 to exit: ");
                    iNum = MyInput();
                    while ((iNum>=1)&&(iNum<=100));
                         if (iNum==999)
                              System.out.println("\n Goodbye \n");
                    while (!(((iNum>=1)&&(iNum<=100))||(iNum==999)));
                         if ((iNum>=1)&&(iNum<=100))
                              Calculation(a,iNum);
                              TimesTable(a,iNum);
     public static void Calculation(int a[], int iNum) //This part doesn't execute
          for(int j=0;j<a.length;j++)
          a[j]=iNum*(j+1);
     public static void TimesTable(int a[], int iNum)
          for(int i=0;i<a.length;i++)
          System.out.println((i+1)+"     *"+iNum+"     ="+a);