How can I get the CheckBoxList selected values, what I have doesn't seem to work C#.NET/VisualWebPart

I am creating a CheckBoxList in a class file and am using an HTMLTextWriter to render the control.

I'm using the following code to store the selected values in a string:

string YrStr = "";
for (int i = 0; i < YrChkBox.Items.Count; i++)
{
    if (YrChkBox.Items[i].Selected)
    {
        YrStr += YrChkBox.Items[i].Value + ";"; 
    }
}

I stepped through the code and it doesn't seem to hit the inside of the if statement & the selected value attribute is false every time ... Anyone have an idea of how I can address this?

I populate it using the following:

 YrChkBox.Items.Add(new ListItem("Item 1", "Item1"));