Sum of array elements

[anita_86]

Hi again!!
This is my code to add and delete dynamic rows and auto calculate the amount field by multiplying qty and rate.

<form name="staff_reg" action="<?php echo $_SERVER['PHP_SELF']."?".$_SERVER['QUERY_STRING']; ?>" method="post" enctype="multipart/form-data">

<table width="100%" border="0" cellspacing="0" cellpadding="2">

<table border="0" cellpadding="1" cellspacing="0" class="normal-text" align="left">

<tr align="center">

<td width="10" class="forhead" style="white-space:nowrap;">&nbsp;</td>

<td width="92" class="forhead" style="white-space:nowrap;">Qty</td>

<td width="94" class="forhead" style="white-space:nowrap;">Rate</td>

<td width="94" class="forhead" style="white-space:nowrap;">Amount</td>

</tr>

</table>



<tr align="left">

<td class="forhead" style="white-space:nowrap;"><input type="button" value="Add Row" onClick="addRow('dataTable')" >&nbsp;

<input type="button" value="Delete Row" onclick="deleteRow('dataTable')" ></td>

<table border="0" id="dataTable" cellpadding="1" cellspacing="0" class="normal-text">

<tr>

<td width="10" class="forhead" style="white-space:nowrap;"><input type="checkbox" name="chk[]"/></td>

<td width="92" class="forhead" style="white-space:nowrap;">



<input type="text"  name="qty[]"  style="width:80px;" onblur="">



</td>

<td width="94" class="forhead" style="white-space:nowrap;">



<input type="text"  name="rate[]" style="width:80px;" value=""></td>



<td width="94" class="forhead" style="white-space:nowrap;">



<input type="text"  onblur="getValues('qty[]','rate[]','amt[]')" name="amt[]" style="width:80px;"></td>



</tr>

</table>

<table border="0">

<tr>

<td>Total:</td>

<td><input type="text"  name="total[]" style="width:80px;" value=""></td>

</tr>



<tr>

<td colspan="2">

<input name="Submit" type="submit" value="Save" style="text-decoration:none" />

<input type="reset" value="Cancel" onclick="window.location.href='<?php echo $_SERVER['PHP_SELF'];?>'">

</td>

</tr>

</form>

<script type="text/javascript">



    function getValues(objName,objName2,objName3)

    {    

        var var3 = "";

        var arr = new Array();

        arr = document.getElementsByName(objName);

        arr2 = document.getElementsByName(objName2);

        arr3 = document.getElementsByName(objName3);

        for(var i = 0; i < arr.length; i++)

        {

            for(var i = 0; i < arr2.length; i++)

            {

            for(var i = 0; i < arr3.length; i++)

            {

            

                var obj1 = document.getElementsByName(objName2).item(i);

                var var2 = obj1.value;



                var obj = document.getElementsByName(objName).item(i);

                var var1 = obj.value;



                var obj3 = document.getElementsByName(objName3).item(i);

                var var3 = obj3.value;

                var var4 = var1 * var2;

                document.getElementsByName(objName3).item(i).value=var4;



            }        

            }

        }    

        

    }

    

  function addRow(tableID) {

     var table = document.getElementById(tableID);

     var rowCount = table.rows.length;

     var row = table.insertRow(rowCount);

     var colCount = table.rows[0].cells.length;

           for(var i=0; i<colCount; i++) {

               var newcell = row.insertCell(i);

                newcell.innerHTML = table.rows[0].cells[i].innerHTML;

                //alert(newcell.childNodes);

                switch(newcell.childNodes[0].type) {

                    case "text":

                            newcell.childNodes[0].value = "";

                            break;

                    case "checkbox":

                            newcell.childNodes[0].checked = false;

                            break;

                    case "select-one":

                            newcell.childNodes[0].selectedIndex = 0;

                            break;

                }

            }

        }

        

function deleteRow(tableID)

{

            try

                 {

                var table = document.getElementById(tableID);

                var rowCount = table.rows.length;



                    for(var i=0; i<rowCount; i++) 

                        {

                        var row = table.rows[i];

                        var chkbox = row.cells[0].childNodes[0];

            

                        if (null != chkbox && true == chkbox.checked) 

                            {

                            if (rowCount <= 1) 

                                {

                                alert("Cannot delete all the rows.");

                                break;

                                }

                

                            table.deleteRow(i);

                            rowCount--;

                            i--;

                            }



                        }

                    } catch(e) 

                        {

                        alert(e);

                        }

}



</script>

I would like to know that how can I show the value of all the elements in array "amount" in total field??