webbrowser select tag

I am having some problem in filling info in webbrowser control. In HTML document select tag is there. Code is this.

HTML Code:

---

<select class="" id="msg" name="msg" aria-required="true">
                    <option value="" SELECTED >- Select One -</option>
                                            <option value="are u child?" >are u child?</option>                 
                                            <option value="are u adult?" >are u adult?</option>                 
                                            <option value="are u smart?" >are u smart?</option>                 
                                                           
                                  </select>

---

I want to select the option in it, so i am using. This code

WebBrowser1.Document.GetElementById("msg").SetAttribute("value", "are u child?")

But this thing is not working. This code work fine in select option if choice is between single string value or numeric value. . But with this lengthy string, it is not working. is there any issue because of spaces in the string??

just fixed out, problem was with navigation.