form help

[bugaloo]

Hi, not to clued up to building web pages but have just started learning and have got a bit stuck. i am doing the company intranet and trying to put together a form that will allow people to fill in rota requests ans submit them to a folder on the server. I have attached how far i have got but nothings happening !!
script

<?
$comment = $_POST['comment'];
$path = "H:\";
$filename = "comment";
while (file_exists($path.$filename)) 
{
$fnum++;
$filename = "comment".$fnum;
}
$handle = fopen($path.$filename, "w");
fwrite($handle,$comment);
fclose($handle);
?>

and my html form
form method="post" action="H:\under construction\req.cgi">

<font size="5">
<h1 align="center">Rota request form</h1>
<p align="center">add any text here ! </p>
 

your name <input type="text" 
                                    id="fullname" size"25" />
Specific requests <input type="text"
                                    id="specific" size="125" />

</pre></p>
 
<p>check the boxes that apply:<br />
<input type="checkbox" id="selected" unchecked="unchecked" />
Saturday 8-4 <br />
<input type="checkbox" id="selected1" unchecked="unchecked" />
Saturday 11-7 <br />
<input type="checkbox" id="selected2" unchecked="unchecked" />
Saturday 2-10 <br />
<input type="checkbox" id="selected3" unchecked="unchecked" />
Saturday day off <br />
<input type="checkbox" id="selected4" unchecked="unchecked" />
Sunday 8-4 <br />
<input type="checkbox" id="selected5" unchecked="unchecked" />
Sunday 11-7 <br />
<input type="checkbox" id="selected6" unchecked="unchecked" />
Sunday 2-10 <br /><input type="submit" value="click here to submit" />
<input type="reset" value=Erase and start over" /></p>

</form>

Any ideas would be great, thanks very much