歌曲列表的编辑和删除问题

我的目的是想编辑和删除歌曲列表中（list.php)中的内容同时也编辑删除歌曲列表（list.xml）的内容
原列表(list.xml)的格式如下：
2|290|2|吻别|1272352617| //2代表音乐分类，如：流行歌曲；290代表音乐歌手；2音乐ID；吻别代表音乐名称；1272352617代表歌手编号
5|230|1|练习|1272344475|
.
.
.
现我已想增加一个这格的歌曲列表，现列表格式如下：
<list>
<m type='' src='http://119.147.241.221/st002.static.360quan.com/music/e7/82/02/webie.mp3' lrc='http://lzkw.freehostia.com/mmv/cmp/lrc/2.lrc' label='吻别' />
</list>
<list>
<m type='' src='http://119.147.241.221/st002.static.360quan.com/music/e7/82/02/lianxi.mp3' lrc='http://lzkw.freehostia.com/mmv/cmp/lrc/2.lrc' label='练习' />
</list>
.
.
.
我的目的是编辑删除歌曲列表(list.php)中的内容也同时编辑歌曲列表(list.xml)中的相对应内容。新增歌曲我已修改成功了，但是编辑删除我不懂修改，望高人帮我修改一下，小弟不胜感谢！！！

后台上编辑和删除文件（edit.php)内容如下。
<?php
!function_exists('adminmsg') && exit('Forbidden');
$basename="$admin_file?adminjob=edit";

function showsinger() {
  global $datadir;
$list=file(R_P."$datadir/singer.php");
$count=count($list);
echo "-->\n";
for ($i=0; $i<$count; $i++) {
  $detail=explode("|",$list[$i]);
echo "subcat[$i] = new Array(\"$detail[2]\",\"$detail[0]\",\"$detail[1]\");\n";
}
echo "onecount=$count;\n";
echo "<!--";
}

function showcat() {
  global $datadir,$catid;
  $list=file(R_P."$datadir/cat.php");
$count=count($list);
echo "-->\n";
for($i=0; $i<$count; $i++) {
$detail=explode("|",$list[$i]);
if($catid==$detail[0])
echo "<OPTION VALUE=\"$detail[0]\" selected>$detail[1]</OPTION>\n";
  else echo "<OPTION VALUE=\"$detail[0]\" >$detail[1]</OPTION>\n";
}
echo "<!--";
}

function get_music_list($page){
global $datadir,$perpage,$basename;

  if(empty($page) or $page<=0) $page=1;
  settype($page, integer);
  
  $mlist=file(R_P."$datadir/list.php");
$count=count($mlist);
$list_info="";
echo "-->\n";
if($count!=0){
if ($count%$perpage==0) $maxpageno=$count/$perpage;
else $maxpageno=floor($count/$perpage)+1;
if ($page>$maxpageno) $page=$maxpageno;
$pagemin=min( ($page-1)*$perpage , $count-1);
$pagemax=min( $pagemin+$perpage-1, $count-1);

for ($i=$pagemin; $i<=$pagemax; $i++) {
$detail=explode("|",$mlist[$i]);
  $pubtime=date("Y.m.d H:i",$detail[4]);
$list_info.="<tr class=bg><td width=\"10%\" height=25 align=\"center\">$detail[2]</td><td width=\"62%\"><a href=\"play.php?id=$detail[2]\" target=_blank>$detail[3]</td><td width=\"18%\" align=\"center\">$pubtime</td><td width=\"5%\" align=\"center\"><a href=\"$basename&editID=$detail[2]&action=edit\">编辑</a></td><td width=\"5%\" align=\"center\"><input type=\"checkbox\" name=\"delID[]\" value=\"$detail[2]\"></td></tr>\n";
}
echo $list_info;
}
else{
$list_info.="<tr class=bg><td colspan=5>暂时还没有音乐列表信息</td></tr>";
echo $list_info;
}
$pageurl="$basename&";
  PageNav($maxpageno,$count,$page,$pageurl,5);
echo "<!--";
}

if (empty($action)){
  include PrintEot('edit');
exit;
  
}elseif ($action=="edit"){
if(empty($editID) || !file_exists(R_P."$datadir/data/$editID.php")) {  
adminmsg('此音乐不存在，可能已被删除');
exit;}
$info=@file(R_P."$datadir/data/$editID.php");
list($catid,$singerid,$songname,$songurl,$hot,$commend,$pubtime)=explode("|",$info[1]);
$statlist=explode("|",$info[2]);
$s_list[2]=implode("|",$statlist);

  if(!$step){
get_catid($catid);
  get_singerid($catid,$singerid);
if($hot==1) $show_1hot='selected';
  elseif($hot==2) $show_2hot='selected';
  elseif($hot==3) $show_3hot='selected';
  elseif($hot==4) $show_4hot='selected';
  elseif($hot==5) $show_5hot='selected';
  if($commend=="yes") $show_1commend='selected'; else $show_2commend='selected';
  include PrintEot('edit');
exit;
}
elseif($step=='2'){
  $song_name=stripslashes($song_name);  
$song_url=stripslashes($song_url);
$song_name=safeconvert($song_name);
$song_url=safeconvert($song_url);
$catid=$_POST['catid'];
$singerid=$_POST['singerid'];
$newlist=$catid."|".$singerid."|".$editID."|".$song_name."|".$timestamp."|\n";
$commendlist=$newlist;
text_modify(R_P."$datadir/list.php",$editID,"|","2",$newlist);

if($commend=="yes" && $newcommend=='yes'){
text_modify(R_P."$datadir/commend.php",$editID,"|","2",$newlist);
}elseif($commend=="no" && $newcommend=='yes'){
  $filecommend=readfrom(R_P."$datadir/commend.php");
if (isset($filecommend)) $commendlist.=$filecommend;
writeto(R_P."$datadir/commend.php",$commendlist);
}elseif($commend=="yes" && $newcommend=='no'){
text_delete(R_P."$datadir/commend.php",$editID,"|","2");
}
$id_line=array($catid,$singerid,$song_name,$song_url,$newhot,$newcommend,$pubtime);
$line=implode("|",$id_line);
  $linee="<? exit;?>\n $line $s_list[2]";
writeto(R_P."$datadir/data/$editID.php",$linee);
@extract($GLOBALS, EXTR_SKIP);

if($_FILES['fileup']['tmp_name']==""){
$upload_file=$_FILES['fileup']['tmp_name'];
  $upload_filename=$_FILES['fileup']['name'];
  $ext = strtolower(strrchr($upload_filename,'.'));
  $lrcname=$editID.".lrc";
if($ext==".lrc"){
  @move_uploaded_file ($upload_file,$datadir."/lrc/".$lrcname);  
}
else { adminmsg('音乐成功修改，但歌词文件不是LRC文件'); exit; }
}
  adminmsg('完成相应操作');
}

}elseif($action=='del'){
  $delID = $_POST['delID'];
foreach ( (array) $delID as $ID) {
unlink(R_P."$datadir/data/$ID.php");
if(file_exists(R_P.$datadir."/lrc/$ID.lrc")) unlink(R_P.$datadir."/lrc/$ID.lrc");
text_delete(R_P."$datadir/list.php","$ID","|","2");
text_delete(R_P."$datadir/commend.php","$ID","|","2");
text_delete(R_P."$datadir/viewhot.php","$ID","|","2");
text_delete(R_P."$datadir/downhot.php","$ID","|","2");
}
adminmsg('完成相应操作');
}
?>