private void WSetTextAndSelection(string text, int selectionStart, int selectionLength)
{
var cps = (ICaretPositionPattern)_wAdvancedTextBoxElement.GetCurrentPattern(CaretPositionPattern.Pattern);
var value = (ValuePattern)_wAdvancedTextBoxElement.GetCurrentPattern(ValuePattern.Pattern);
value.SetValue(text);
cps.SetSelectionStart(selectionStart);
cps.SetSelectionLength(selectionLength);
}