function calculate(){
        var textFields = document.getElementsByName('textfield23');
        var total = 0;

        for(var i in textFields){
            if(textFields[i].value){
                total += parseFloat(textFields[i].value);
            }
        }

        document.getElementById('textfield19').value = total;

<?php

foreach($textfield23 as $a => $b){
$qins = "INSERT INTO myTable VALUES(NULL, $reqid, $selecta[$a], '$textfield23[$a]', '', '', NOW())";
mysql_query($qins) or die(mysql_error());
";

}

?>

<script language="javascript">
function calcvaluesArr(){
var txts = document.getElementsByName('textfield23[]');
		var aTotal=0;                      
		 for (var i = 0; i < txts.length; i++) 
          {         
            if (txts[i].value!="") 
               { 
				aTotal=eval(aTotal)+eval(txts[i].value);
              } 
        } 
document.form.textfield19.value=aTotal;