<form id="form_1">
<input type="text" name="a1">
<input type="text" name="a2" value="5">
<select name="a3">
<option value=""></option>
<option value="0">0</option>
<option value="1">1</option>
</select>
<input type="submit" value="go">
</form>
-----------------------------------------------------------------------
name = a1 value = , type = string
name = a2 value = 5 , type = string
name = a3 value = , type = string
