Hellihello Marcel,
s.a. http://html-ag.wvs-berlin.de/PHP_Tests/checkboxen_vorselektieren.php
<form name="form" method="get" action="">
<br>
c1: <input type="checkbox" name="c1" <?php if (isset($_REQUEST["c1"])) echo "checked";?>>
<br>
c2: <input type="checkbox" name="c2" <?php if (isset($_REQUEST["c2"])) echo "checked";?>>
<br>
c3: <input type="checkbox" name="c3" <?php if (isset($_REQUEST["c3"])) echo "checked";?>>
<br>
<input type="submit">
</form>
Dank und Gruß,
frankx