you have 2 separate forms, one for the file field and one for the submit button.
the file field and submit button should be in the same form:
<form id="form1" name="form1" enctype="multipart/form-data" method="post" action="">
<label>upload file
<input type="file" name="upload" id="upload" />
</label>
<label>
<input type="submit" name="submit" id="submit" value="Submit" />
</label>
</form>