checkboxes and php

I have checkboxs in a form for deletion <input type=checkbox name="materialid<? echo $row["material_id"];?>"> The above code create a checkbox for each row in the table. I would like to delete multiple records using the above. if i check 3 checkboxes for deletion and use matid1=$HTTP_POST_VARS["materialid$matid"]; to find out if the checkbox is checked. It works for the checkboxes that are checked but gives me an error for the unchecked checkboxes. Erro message: Notice: Undefined index: materialid1020 in e:\..scripts\asset_delete2.php on line 17 Notice: Undefined index: materialid1030 in e:\..scripts\asset_delete2.php on line 17 and so on. How can i skip the ones i dont check at all or skip the error message frm showing. I dont care about the ones i dont check in the previous form. Thanks,