<form>
<select onchange="this.options[this.selectedIndex].text=='是'?input1.style.display=input2.style.display='':input1.style.display=input2.style.display='none'">
<option value="1" selected>是</option>
<option value="0">否</option>
</select>
<input type="text" value="11111111" id="input1" name="input1"> <input type="text" value="222222222" id="input2" name="input2">
</form>