title: get selectedValue of dropdownlist from code behind
body: <p>On an aspx page I have a dropdownlist and a button. </p>
  
  <p>I select a value from the dropdownlist and click the button.</p>
  
  <p>In the button event handler I have the statment: DropDownList1.SelectedValue;</p>
  
  <p>This value is showing up as the first item in the list regardless of what item is actually selected.</p>
  
  <p>Same result with .SelectedItem.Value and .Text</p>
  
  <p>Why? And how do I get the item actually selected?</p>