Text extractor - by MikiSoft

<head><title>Text extractor - by MikiSoft</title></head>
<body>
<h1>Extractor</h1>
<form name="extract" action="<?php echo $PHP_SELF; ?>" method="post">
<textarea rows="15" cols="65" name="text"><?php echo $_POST['text']; ?></textarea>
<p><label for="before">Between: </label><input type="textbox" name="before" value="<?php echo $_POST['before']; ?>" size="15" /><label for="after"> and: </label><input type="textbox" name="after" value="<?php echo $_POST['after']; ?>" size="15" /> <input type="checkbox" name="revert" value="1"><label for="revert"> Revert</label> | <select name="type"><option value="0" selected="selected">All</option><option value="1">Pair</option><option value="2">Odd</option></select> <input type="checkbox" name="reverse" value="1"><label for="reverse"> Reverse</label></p>
<h6 style="position:relative;top:-20px">Note: type [[NL]] for new line.</h6>
<input type="submit" value="Extract" style="position:relative;top:-30px" />
</form>
<?php
if($_POST["text"]=="" || $_POST["before"]=="" || $_POST["after"]==""){
echo "</body>";
exit;
}
if(strpos($_POST["text"], str_replace("[[NL]]","\n",$_POST["after"]))===false || strpos($_POST["text"], str_replace("[[NL]]","\n",$_POST["before"]))===false){ exit; }
$text = $_POST["text"];
$before = str_replace("[[NL]]","\n",$_POST["before"]);
$after = str_replace("[[NL]]","\n",$_POST["after"]);
if($_POST["revert"]==1){ $extract = explode($after, $text); }else{ $extract = explode($before, $text); }
$c = 0;
if($_POST["type"]!=0){ $c1 = -1; }
for($i=1;$i<count($extract);$i++){
if($_POST["type"]==1){
if(($c+1) % 2 == 0) { $c1++; if($_POST["revert"]==1){ $extract1 = explode($before, $extract[$i-1]); $str[$c1] = $extract1[count($extract1)-1]; }else{ $extract1 = explode($after, $extract[$i]); $str[$c1] = $extract1[0];} }
} elseif($_POST["type"]==2){ if(($c+1) % 2 != 0){ $c1++; if($_POST["revert"]==1){ $extract1 = explode($before, $extract[$i-1]); $str[$c1] = $extract1[count($extract1)-1]; }else{ $extract1 = explode($after, $extract[$i]); $str[$c1] = $extract1[0];} }
} else { if($_POST["revert"]==1){ $extract1 = explode($before, $extract[$i-1]); $str[$c] = $extract1[count($extract1)-1]; }else{ $extract1 = explode($after, $extract[$i]); $str[$c] = $extract1[0];} }
$c++;
}
echo "Extracted:<br><textarea rows=\"15\" cols=\"50\" name=\"extracted\">";
if($_POST["reverse"]==1){
for($i=count($str);$i>=0;$i--){
echo $str[$i]."\r\n";
}
} else {
foreach ($str as $extracted){
echo $extracted."\r\n";
}
}
echo "</textarea>\r\n</body>";
?>