Ungke

<script language="javascript">
    function addsum(){
        var tot=0;
        var count = document.getElementsByName('input[]');

        for(i=0; i<count.length; i++){
            tot = tot + parseInt(count[i].value);
        }

        document.fr_income.tx_total.value=tot;
    }

    function addsum2(){
        var tot=0;
        var count2 = document.getElementsByName('bertho[]');

        for(i=0; i<count2.length; i++){
            tot = tot + parseInt(count2[i].value);
        }

        document.fr_income.tx_total2.value=tot;
    }

    function addsum3(){
        var tot=0;
        var count3 = document.getElementsByName('firman[]');

        for(i=0; i<count3.length; i++){
            tot = tot + parseInt(count3[i].value);
        }

        document.fr_income.tx_total3.value=tot;
    }
</script>
<form action="" method="post" name="fr_income" id="fr_income">
    <table>
        <tr>
            <td>Nilai Siswa Ungke</td>
        </tr>
        <tr>
            <td>Matematika</td>
            <td>:</td>
            <td><input type='text' name='input[]' id='input[]' class='form_field' onkeyup='addsum()' value='0' /></td>
        </tr>
        <tr>
            <td>IPA</td>
            <td>:</td>
            <td><input type='text' name='input[]' id='input[]' class='form_field' onkeyup='addsum()' value='0' /></td>
        </tr>
        <tr>
            <td>IPS</td>
            <td>:</td><td>
            <input type='text' name='input[]' id='input[]' class='form_field' onkeyup='addsum()' value='0' /></td>
        </tr>
        <tr>
            <td>Total</td>
            <td>:</td>
            <td><input type="text" name="tx_total" id="tx_total" disabled="disabled" /></td>
        </tr>
    </table>
    <br>
    <br>
    <table>
        <tr>
            <td>Nilai Siswa Bertho</td>
        </tr>
        <tr>
            <td>Matematika</td>
            <td>:</td>
            <td><input type='text' name='bertho[]' id='bertho[]' class='form_field' onkeyup='addsum2()' value='0' /></td>
        </tr>
        <tr>
            <td>IPA</td>
            <td>:</td>
            <td><input type='text' name='bertho[]' id='bertho[]' class='form_field' onkeyup='addsum2()' value='0' /></td>
        </tr>
        <tr>
            <td>IPS</td>
            <td>:</td><td>
            <input type='text' name='bertho[]' id='bertho[]' class='form_field' onkeyup='addsum2()' value='0' /></td>
        </tr>
        <tr>
            <td>Total</td>
            <td>:</td>
            <td><input type="text" name="tx_total2" id="tx_total2" disabled="disabled" /></td>
        </tr>
    </table>
    <br>
    <br>
    <table>
        <tr>
            <td>Nilai Siswa Firman</td>
        </tr>
        <tr>
            <td>Matematika</td>
            <td>:</td>
            <td><input type='text' name='firman[]' id='firman[]' class='form_field' onkeyup='addsum3()' value='0' /></td>
        </tr>
        <tr>
            <td>IPA</td>
            <td>:</td>
            <td><input type='text' name='firman[]' id='firman[]' class='form_field' onkeyup='addsum3()' value='0' /></td>
        </tr>
        <tr>
            <td>IPS</td>
            <td>:</td><td>
            <input type='text' name='firman[]' id='firman[]' class='form_field' onkeyup='addsum3()' value='0' /></td>
        </tr>
        <tr>
            <td>Total</td>
            <td>:</td>
            <td><input type="text" name="tx_total3" id="tx_total3" disabled="disabled" /></td>
        </tr>
    </table>

</form>