Send Data From A Combo Box To A Text Field

I use dreamweaver and i have a combobox named country and a text field named email. I want the user choose a country from the combobox and the email for this country go to a text field. Lets say the user choose England from the combobox and an email will be puted in text box. I use PHP or ASP. This is my form:

<td><select name="country" id="country">
<option>1</option>
<option>2</option> </select>

<input name="email" type="text" id="email" value="email for the country in combo box"> </td>