select的查詢問題

[freekite]

<form name="form1" method="POST" >
<p><select size="1" name="D1">
<option value="1">AAAA</option>
<option value="2">BBBB</option>
<option value="5">CCCC</option>
<option value="7">DDDD</option>
</select>
<input type="text" name="T1" size="20">
<input type="button" value="按鈕" name="B1"></p>
</form>
怎樣在T1中輸入"C"　點B1，D1定位在"CCCC"上？

[cpp2017]

<SCRIPT ID=clientEventHandlersJS LANGUAGE=javascript>
<!--

function form1_onclick() {
for (var i=0;i<form1.D1.options.length;i++)
{
if(form1.D1.options[i].text.substring(0,1) ==form1.T1.value)
{
form1.D1.options[i].selected = true;
}
}



}

//-->
</SCRIPT>
<form name="form1" method="POST" LANGUAGE=javascript onclick="return form1_onclick()">
<p><select size="1" name="D1">
<option value="1">AAAA</option>
<option value="2">BBBB</option>
<option value="5">CCCC</option>
<option value="7">DDDD</option>
</select>
<input type="text" name="T1" size="20">
<input type="button" value="按鈕" name="B1"></p>
</form>

[xgtqr123]

把d1中的值写进数组中吧，点b1时调用javascript脚本，进行检查，相配，就移到相应位置上就可了