Radio button problem

[shiva05]

Hi frnds,
I have a problem with radio button.
I am using the below(check1 function) to display the length of the radio button.
If it has more than 1 row it alerts correctly but if it has only 1 row it says undefined what is the problem

function check1()
	{
		var len;
		len = document.artist.radio1.length;
	    alert('rows '+len);
	
	//len = document.getElementById('radio1');
	for (i= 0;i < len ;i++){
		
		if (document.artist.radio1[i].checked == true)
		t = document.artist.radio1[i].value;
         
		}
	 document.artist.hid1.value = t;
	 alert(t);	
		
	}

while ($rowsql1 = mysql_fetch_array($rssql1))
{
	$countr = $countr + 1;
$products_id=$rowsql1['products_id'];
$products_name=$rowsql1['products_name'];
$categories_id=$rowsql1['categories_id'];
$refid = $rowsql1['ref_id'];
$new=$rowsql1['new'];
$p=$rowsql1['products_quantity'];
	//echo $products_name;
$sqlcategories="select categories_name from categories_description where categories_id='$categories_id'";
$rscategories = mysql_query($sqlcategories) or die ("couldn't find a record");
echo "row".$categories_id;
$c = mysql_fetch_row($rscategories);
$categories_name = $c[0]; 

if ($rowcategories == mysql_fetch_array($rscategories))
{
	$categories_name=$rowcategories['categories_name'];
}

<td align="center"><input type="radio" id="radio1" value="<? echo $products_id; ?>" onclick="check1();"></td>

[gits]

please post an example of the generated html-code so that we may see what the function will do during runtime.

kind regards