title: Validate on Button1 click, but not Button2
body: <p>I have two buttons, a text box, and a combo box on a page:</p>
  
  <p>The user inputs an integer to search for in the text box, and presses the Find button. A data grid is populated, the user selects a row, and clicks the Print button.</p>
  
  <p>I want the Print button to validate that a selection has been made in the combo box (i.e. selectedindex is not -1). The combo box is an ASPxComboBox (DevExpress control). On the ComboBox, RequiredField.IsRequired is set to True. However, this causes the ComboBox to be validated on click of both Find AND on Print. Validation should not happen on click of the Find button.</p>
  
  <p>How can I force a selection in my combobox on click of one button but not another?</p>