08.Prime Number Check

using System;

class Prime
{
    static void Main()
    {
        Console.Write("Enter a positive integer numbers(from 1 to 100):");
        int numInt=int.Parse(Console.ReadLine());
        Console.WriteLine("\n");

        if (numInt < 0)
        {
            Console.WriteLine("Invalid range!");
            Console.WriteLine("\n");
            return;
        }
        Boolean greaterNum=(numInt>1);

        if (greaterNum)
        {
                int intCountDivide = numInt-1;
                Boolean checkNum = ((numInt % intCountDivide) != 0);

              while (checkNum)
              { //While loop checks whether the entered 
               //number is divisible without remainder
              //to other number except 1.
                  intCountDivide=intCountDivide-1;
                  checkNum=((numInt%intCountDivide)!=0);
                  //It is imperative to check inside the 
                  //cycle of not to hangup program.
              }
              Boolean onlyNumDivide = ((intCountDivide==1)&&(numInt%numInt==0));

              if (onlyNumDivide)
              {
                 Console.WriteLine("The number {0} is prime:", numInt);
                 Console.WriteLine("\n");
              }
              else
             Console.WriteLine("The number {0} isn't prime:",numInt);
        }
        else
            Console.WriteLine("The number {0} isn't prime:",numInt);
            Console.WriteLine("\n");
    }
}