Was mache ich falsch?

<form action="save.php" method="POST">
<fieldset name="fsetFormular" id="fsetFormular">
<legend name="lblFormular" name="lblFormular">Dein Eintrag ins Weblog</legend>
<table align="center" width="400"> 
<tr>
<td>Name</td>
<td><input type="text" class="EntryField" name="txtNickname" id="txtNickname" maxlength="255" size="42"></td>
</tr>
<tr>
<td>eMail</td>
<td><input type="text" class="EntryField" name="txtEmail" id="txtEmail" maxlength="255" size="42"></td>
</tr>
<tr>
<td>Homepage</td>
<td><input type="text" class="EntryField" name="txtHomepage" id="txtHomepage" maxlength="255" size="42" value="http://"></td>
</tr>
<tr>
<td valign="top">Dein Eintrag</td>
<td><textarea class="EntryField" name="txtMessage" id="txtMessage" rows="10" cols="40"></textarea></td>
</tr>
</table>
<table align="center" width="400">
<tr>
<td align="right"><input type="submit" value="Eintragen" class="cmdButton"></td>
<td align="left"><input type="reset" value="Löschen" class="cmdButton"></td>
</tr>
</table>
</fieldset>
</form>

<?php
		//mysql_connect("localhost","benutzer","passwort");
		//mysql_select_db("cmonline");
		$datum = date("d.m.Y");
		$sql = "insert into gbook (nickname, email, homepage, message, datum) ";
		$sql = $sql."values(\"$txtNickname\", ";
		$sql = $sql."\"$txtEmail\", ";
		$sql = $sql."\"$txtHomepage\", ";
		$sql = $sql."\"$txtMessage\", ";
		$sql = $sql."\"$datum\")";
		echo $sql;
		//mysql_query($sql);
		echo mysql_error();
		//mysql_close();
	?>