php formular: texteingabe hat immer am anfangszustand 24 Leerzeichen, aber wieso?

<?php

    $tag1 = "";

    $tag2 = "";

    $tag3 = "";

    $name = trim("");

    $nachname = "";

    if(isset($_POST['tag1'])){

        $tag1 = "X";

    }

    else{

        $tag1 = "-";

    }

    if(isset($_POST['tag2'])){

        $tag2 = "X";

    }

    else{

        $tag2 = "-";

    }

    if(isset($_POST['tag3'])){

        $tag3 = "X";

    }

    else{

        $tag3 = "-";

    }

    if(isset($_POST['nm_text'])){

        $name = trim($_POST['nm_text']);

    }

    if(isset($_POST['nm_nachname'])){

        $nachname = trim($_POST['nm_nachname']);

    }

    if(empty($name) OR empty($nachname))   { ?>

        <form name="nm_umfr" action="umfragespeichern.php" method="post" enctype="text/html">

            Vorname:

            <input type="text" name="nm_text" value="

            <?php echo "$name"; ?>

            " size="25" maxlength="25" />

            <br />

            Nachname:

            <input type="text" name="nm_nachname" value="

            <?php echo "$nachname"; ?>

            " size="25" maxlength="25" />

            <br />

            <input type="checkbox" name="tag1"

            <?php if($tag1 == "X"){

                echo "checked='checked'";

            } ?>

             />

            <input type="checkbox" name="tag2"

            <?php if($tag2 == "X"){

                echo "checked='checked'";

            } ?>

            />

            <input type="checkbox" name="tag3"

            <?php if($tag3 == "X"){

                echo "checked='checked'";

            } ?>

            />

            <input type="submit" name="nm_submit" value="Save" />

        </form>            <?php

    }

    else{

        $dateiname = "umfrage.txt";

        //echo "$tag1";

        $DATEI = fopen($dateiname, "a");

        fwrite($DATEI, $tag1 . "|" . $tag2 . "|" . $tag3 . "|". $name . $nachname. "\r\n");

        fclose($DATEI);

        echo"Danke!";

    }

?>