validateForm for循环中的数据

Question

I'm new here and my english is not perfect.

I want to validateForm that examined the forms are not empty or if the data are numbers. If not, then the message and I would like to previous data in forms have. If so, then the message and redirect to another page.

Forms are created in the loop: for. I can not find a solution, I tried in javascript, but maybe you know other solutions. Thank you.

<form name="ilosc" method="post" action="test5.php" onsubmit="return validateForm();" action="#">
<?php

            for($i = 1; $i <= $num_rows; $i++) 
                {
                echo '<tr><td><input type="text" size=7 name="xxx['.$i.'][ilosc]"/></td></tr>'; 
                }
            echo    '<p><input type="button" value="...Add..." onclick="validateForm()"/></p></form>';

         ?>
        <script type="text/javascript">
        function validateForm() {
        var x = document.forms["ilosc"]["xxx['.$i.'][ilosc]"].value;
        if (x==null || x=="") {
          alert("Stop");
        }
        else
            document.form.submit();
        }
        </script>`