Value of Property

I'm using the property Myval to prevent the dropdown listbox from resetting its value.
The problem is Myval  remains 0 into the 2nd call of the PreRender where it was set to 1 on the previous call.
Not sure why its doing this. Can you help?
 
public partial class HomePage : System.Web.UI.Page
{

    Print myval;
    public int Myval
    {
        get
        {
            return myval;
        }
        set
        {
            myval = value;
        }
    }
   
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