JQuery Mobile Submission Form Questions

JQuery Mobile Submission Form Questions

First let me preface this by saying I'm new to JQuery Mobile and still trying to figure it out.

My issue is I have created a submission form and I have a few questions:

1. How do I make certain fields mandatory?

2. I have it set up so that the user selects who they want to send the form to from a drop down menu using the following example of code.  Is this correct?
<label for="select-choice-0" class="select">Select:</label>
<select name="select-choice-0" id="select-choice-1"> 
   <option value="none"></option>
   <option value=" sample1@yahoo.com">Sample 1</option>
   <option value=" sample2@yahoo.com">Sample 2</option>
</select>

3. How do I get it so the action of pressing the submit button sends the form to the selected contact from the drop down menu? Current code:
<input class="button" type="submit" value="Submit Request"/>

4. I want a message to pop-up saying "Your request has been submitted." After the button is clicked.

5. I want the form to send with a default message at the bottom that the recipient will see, i.e. "This request was sent using the BlahBlahBlah app."

Thanks for you help.