stick them in an array.
<INPUT type="checkbox" name="chkbox[]" value="1">
<INPUT type="checkbox" name="chkbox[]" value="2">
<INPUT type="checkbox" name="chkbox[]" value="3">
<INPUT type="checkbox" name="chkbox[]" value="4">
<INPUT type="checkbox" name="chkbox[]" value="5">
<INPUT type="checkbox" name="chkbox[]" value="6">
you then end up with an array of the checked values.
Mark.