php文件上传的有关问题

<br /><form action = "upload_file.php" method = "post" enctype = "multipart/form-data"><br /><label for = "file">Filename</label><br /><input type = "file" name = "file" id = "file"/><br /><br><br /><input type = "submit" name = "submit" value = "上传"/><br /><br /></form><br />

<br /><?php<br />if($_FILES["file"]["error"] > 0)<br />{<br />	echo "Error : ".$_FILES["file"]["error"]."<br>";<br />}<br />else<br />{<br />	echo "Upload: ".$_FILES["file"]["name"]."<br>";<br />	echo "Type: ".  $_FILES["file"]["type"]."<br>";<br />	echo "Size: ".($_FILES["file"]["size"]/1024)."KB<br>";<br />	echo "Stored in: ".$_FILES["file"]["tmp_name"]."<br>";<br />	<br />	if(file_exists("upload/".$_FILES["file"]["name"]))<br />	{<br />		echo $_FILES["file"]["name"]." already exists.";<br />	}<br />	else<br />	{<br />		//move_uploaded_file($_FILES["file"]["tmp_name"], "upload/".$_FILES["file"]["name"]);// 报错<br />		move_uploaded_file("upload/".$_FILES["file"]["name"],$_FILES["file"]["tmp_name"]);<br />		echo "<br><br><br> Storeed in: "."upload/".$_FILES["file"]["name"];<br />	}<br />	<br /><br />}<br /><br /><br /><br />?><br />