>It's also possible to instantiate Helper each time you need it, then it won't be a member of neither test1 nor test2
>
>

>	public class test1
>	{
>		SumHelper Helper = new SumHelper();
>
>		public void test()
>		{
>			List<int> theList = new List<int> { 1, 2, 3, 4 };
>
>			int result = Helper.Sum(theList);
>		}
>	}
>
>	public class test2
>	{
>		SumHelper Helper = new SumHelper();
>
>		public void test()
>		{
>			List<int> theList = new List<int> { 7,8,9,10 };
>
>			int result = Helper.Sum(theList);
>		}
>	}
>
>	public class SumHelper
>	{
>		public int Sum(List<int> theList)
>		{
>			int total = 0;
>			foreach (int item in theList)
>			{
>				total += item;
>			}
>			return total;
>		}
>	}
>

>An alternative (suggested by Tim) is to have a helper class with a static method
>
>

>	public class test1
>	{
>
>		public void test()
>		{
>			List<int> theList = new List<int> { 1, 2, 3, 4 };
>
>			int result = SumHelper.Sum(theList);
>		}
>	}
>
>	public class test2
>	{
>
>		public void test()
>		{
>			List<int> theList = new List<int> { 7,8,9,10 };
>
>			int result = SumHelper.Sum(theList);
>		}
>	}
>
>	public class SumHelper // the class should be static if all of its methods are static
>	{
>		public static int Sum(List<int> theList)
>		{
>			int total = 0;
>			foreach (int item in theList)
>			{
>				total += item;
>			}
>			return total;
>		}
>	}
>

I have another scenario where I think I need some common Helper class - but not 100% sure how to implement. I have two forms where I have Customer Combobox. I need to Load the entries to it. This is the method that does it currently (coded in one of the forms)

private void LoadCustomersCombo()
        {
            //set up the customer datasource for the drop down.
            Dictionary<Guid, string> _customersEntries = this._CustomerListBiz.GetCustomersDictionary();
            this.cboCustomer.Items.Clear();

            this.cboCustomer.DisplayMember = "Value";
            this.cboCustomer.ValueMember = "Key";

            foreach (KeyValuePair<Guid, string> kvp in _customersEntries)
            {
                this.cboCustomer.Items.Add(kvp);
            }
        }

where _customerEntries is a private property of the form.

Now, how would I change this to use the Helper class instead?

Thanks again.

UPDATE. Solved.