how to convert install_amt to comma delimited array
$select = mysql_query("SELECT ac_no,cust_name,install_amt,GROUP_CONCAT(install_amt) FROM ankali_slabpay WHERE agent_id=$agent_id GROUP BY ac_no");
$a=array();
while($row1 = mysql_fetch_assoc($select)){
$installment = $row1['GROUP_CONCAT(install_amt)'];
$a=explode(",",$installamt);