<html>
<head>
<title>Classroom research</title>
</head>
<body>
<h1>CRMS - Classroom research</h1>
<form action="research.php" method="post">
<table border="0">
<tr>
<td>Classroom ID</td>
<td><input type="text" name="Cno" maxlength="13" size="13"></td>
</tr>
<tr>
<td>Course ID</td>
<td>
<select>
<option value=0>--请选择--</option>
<?php
$con = mysql_connect("localhost","root","");
$search_course = "SELECT CID FROM course2";
$result = mysql_query($search_course, $con);
while($row = mysql_fetch_array($result))
{
<option value="$row">$row</option>
}
?>
</select>
</td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="Register"></td>
</tr>
</table>
</form>
</body>
</html>
1、我希望在第一个框输入课室号，第二框通过下拉框显示数据库中course2表的CID的内容。
这应该就是不对的，毫无头绪，不知道怎么实现。求详细代码！
2、怎样实现填写其中一个数据（即不用填两个）就可以查询数据？
------解决方案--------------------
仅供参考：
- PHP code
<?php/* Created on [2012-5-16] */#查询标题信息$sql="select * from table"; $res=mysql_query($sql); if(!$res) die("SQL: {$sql} <br>Error:".mysql_error()); if(mysql_affected_rows() > 0){ $titles = array(); while($rows = mysql_fetch_array(MYSQL_ASSOC)){ array_push($titles,$rows); } }?><table border=1><?php foreach($titles as $row_Recordset_task){ ?> <tr> <td> <a href="javascript:void(0)" onclick="record(<?=$row_Recordset_task['TID']?>)" > <?=$row_Recordset_task['csa_title']?> </a> </td> </tr><?php } ?></table><div id="show"></div><form name="frm"><select name="s1" onChange="redirec(this.value)"> <option selected>请选择</option> <option value="1">内科</option> <option value="2">内科</option> <option value="3">内科</option></select><div id="s2"></div></form><script>//Ajaxvar xmlHttp; function createXMLHttpRequest() { if(window.XMLHttpRequest) { xmlHttp = new XMLHttpRequest(); } else if (window.ActiveXObject) { xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); } } function record(id){ createXMLHttpRequest(); url = "action.php?id="+id+"&ran="+Math.random(); method = "GET"; xmlHttp.open(method,url,true); xmlHttp.onreadystatechange = show; xmlHttp.send(null); } function show(){ if (xmlHttp.readyState == 4){ if (xmlHttp.status == 200){ var text = xmlHttp.responseText; document.getElementById("s2").innerHTML = text; }else { alert("response error code:"+xmlHttp.status); } } }</script><?php#action.phpif(isset($_GET['id'])){ $sql="select * from table where id=".$_GET['id']; $res=mysql_query($sql); if(!$res) die("SQL: {$sql} <br>Error:".mysql_error()); if(mysql_affected_rows() > 0){ $arrMenu=array(); while($rows = mysql_fetch_array(MYSQL_ASSOC)){ array_push($arrMenu,$rows); } } mysql_close(); if(!empty($arrMenu)){ echo "<select name='menu2'>"; foreach($arrMenu as $item2){ echo "<option value='{$item2['id']}'>{$item2['name']}</option>"; } echo "</select>"; }}?>