The value property returns the value of the option that is selected in that instance of a select box.
<html> <form name="myForm"> <select name="mySelect" onChange='alert(mySelect.options[selectedIndex].value)'> <option value=A>AA</option> <option value=B name=TEST>BB</option> <option value=CC>CC</option> <option value=DD>DD</option> </select> </form> </html>