mshtml: Forward IHTMLWindow2::setInterval to IHTMLWindow3.

dlls/mshtml/htmlwindow.c

@@ -578,8 +578,13 @@ static HRESULT WINAPI HTMLWindow2_setInterval(IHTMLWindow2 *iface, BSTR expressi
         long msec, VARIANT *language, long *timerID)
 {
     HTMLWindow *This = HTMLWINDOW2_THIS(iface);
-    FIXME("(%p)->(%s %ld %p %p)\n", This, debugstr_w(expression), msec, language, timerID);
-    return E_NOTIMPL;
+    VARIANT expr;
+
+    TRACE("(%p)->(%s %ld %p %p)\n", This, debugstr_w(expression), msec, language, timerID);
+
+    V_VT(&expr) = VT_BSTR;
+    V_BSTR(&expr) = expression;
+    return IHTMLWindow3_setInterval(HTMLWINDOW3(This), &expr, msec, language, timerID);
 }
 
 static HRESULT WINAPI HTMLWindow2_clearInterval(IHTMLWindow2 *iface, long timerID)