error: object ref. required for non static field

[Dale]

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;


namespace RabbitGenetics
{
    
    public class JWClass
    {
        //housekeeping
        //Jersey Wooly Color Genetics


        // create list for sire data
        public List<int> siregtype = new List<int>();


        //create list for dam data
        public List<int> damgtype = new List<int>();


        // set sire & dam array size
        public const int rows = 128;
        public const int columns = 7;


        // create lists for dictionaries
        public List<int> colorslist = new List<int>();
        public List<int> gtypelist = new List<int>();


        // create sire & dam data 2D arrays
        public int[,] siredata = new int[rows, columns];
        public int[,] damdata = new int[rows, columns];


        //create offspring 1D array
        public int[] offspring = new int[14];
        
        // create sire & dam 1D arrays
        public int[] sire = new int[14];
        public int[] dam = new int[14];


        //create child 4D array
      //  public int[, , ,] child = new int[color_counter, 4];


        //Dictionaries
        public Dictionary<string, int> colors = new Dictionary<string, int> { };
        public string color; //name key
        Dictionary<string, string> geneo = new Dictionary<string, string> { };
        public string gtype; // geneotype key


        // gene groups
        public int Broken, Agouti, Brown, Colour, Dilute, Ext, Vienna;


        // Vienna types flags
        bool vienna = false; bool vm = false; bool vc = false;


        //color flags
        bool dilute = false; bool charlie = false; bool broken = false; bool rew = false;


        // data holders
        public int sen1, sen2, sa1, sa2, sb1, sb2, sc1, sc2, sd1, sd2, se1, se2, sv1, sv2;
        public int den1, den2, da1, da2, db1, db2, dc1, dc2, dd1, dd2, de1, de2, dv1, dv2;
        public char colorpct;


        //declare counters
        public int sirecounter = 0;
        public int damcounter = 0;
        public int offspringcounter = 0;
        public int totalcount = 0;
        public int color_count = 0;
        // public color_counter = 0;
        public static bool e_trap;


    } // end JWClass


    public class Genetics
    {
      // public JWClass jw;
        
        static void Main()
        {
              var  jw = new JWClass();
          //  obj = new JWClass();


            prog();
            
        } // end Main




        // start program run
          public static  void prog()
      
  {
           //array setup variiables for parsing combinations into the correct fields.
         jw.Broken = (jw.rows / 2);


            return;
        } // end prog

     } // End Class GenticsClass
} // end Namespace RabbitGenetics

I can't figure why I'm getting this error.
I want to access and/or modify vars in class JWClass from class Genetics.
I'm new to C# and OOP programming style.
My background is COBOL using the structured style

[theoobe]

You're attempting to access the non-static instance "jw" from within a static method. Change:

public JWClass jw;

to:

public static JWClass jw;

[Dale]

Thanks. That did the trick.

It then showed another error where I couldn't access var rows.
Seems I can not use an instance to access it. So I used JWClass.rows and it works.

Also found out I can use an instance for all the following vars that reference the var Broken

[nvoigt]

Constants are always static, because they don't change for every instance, so it doesn't make sense to allocate memory for them for every instance.