unable to read checkbox and radio

["Sudhakar" <finals27@xxxxxxxxx>]

i am using a self submitting form

<form action="<?php echo $_SERVER["PHP_SELF"]; ?>" method="POST" 
id="test2" name="test1"> 

i need to do a validation of textfields, checkboxes, radio buttons 

i am able to read, display and validate textfields after the form 
has been submitted however i am getting an error for 

checkbox and radio buttons.

code for textfields

username <input type="text" name="username"  value="<?php echo
($username) ; ?>" />

$username = htmlentities($_POST["username"]);

if($username == "") { $error.=" enter username <br />"; }

for checkboxes and radio buttons i am getting 
"Notice: Undefined index: checkboxname "    for checkbox
"Notice: Undefined index: radiobuttonname " for radio button

presently the code for checkbox and radio button is

<input type="checkbox" name="cbox" value="abc" /> 

$deposit = $_POST["cbox"];


<input type="radio" name="radioname" value="one"> one
<input type="radio" name="radioname" value="two"> two

$radioname = $_POST["radioname"];

i have tried cbox[] radioname[] however i keep getting 
"Notice: Undefined index: cbox " and "Notice: Undefined index: 
radioname "
for checkbox and radio button

please advice.

thanks.