为什么小弟我不会写代码

 <a class="np coolbg" href="student_voice.php?do=add">添加考试</a>

if($_GET['do']=='add'){<br />
    include DedeInclude('templets/student/student_voice_add.htm');<br />
	$id = $_POST['username'];<br />
	$email = $_POST['email'];<br />
	$content = $_POST['content'];<br />
	$time = date('Y-m-d H:i:s');<br />
	$category = $_POST['category'];<br />
	$flag = $_POST['flags'];<br />
	$flags=implode(",",$flag);<br />
	$checked = $_POST['checked'];<br />
	//echo $id."<br/>".$email."<br/>".$content."<br/>".$time."<br/>".$category."<br/>".$flags."<br/>".$checked;<br />
	$sql = "INSERT INTO djs_skstudent_voice (username ,content ,time ,category ,checked ,email ,flag)VALUES ('$id','$content', '$time' , '$category', '$checked','$email','$flags')";<br />
	$dsql->ExecuteNoneQuery($sql);