calculating amount

Hi Friends

I am using dynamic text box, i want to calculate the amount from value of rate in the text box and qty

Pls help me how to solve it...

<?php
	include("config.php");
?>
<script type=text/javascript>
function multiply(){
a = document.getElementById("rate").value;
b = document.getElementById("qty").value;
c = a*b;
amt = 
alert(c);
}
</script>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>

</head>

<body>
<form action="" method="get" name="test">
<table width="800" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td align="center">S.No</td>
    <td align="center">Item Name</td>
    <td align="center">Item Code</td>
    <td height="30" align="center">Rate</td>
    <td align="center">QTY</td>
    <td align="center">Amount</td>
    </tr>
  <tr>
  <?php $desr="select * from site_rate where category_code='EWS001' AND sitename='Amber' order by item_code";
		//echo $desr;
	  	$r=mysql_query($desr,$conn);
	  	$i=1;
		while($m=mysql_fetch_array($r))
		{
			?>
    <td><?php echo $i; ?></td>
    <td><textarea name="cat_item" cols="25" rows="2"><?php echo $m['category_item'];?></textarea></td>
    <td><?php echo $m['item_code'];?></td>
    <td><input name="rate" type="text" id="rate"/></td>
    <td><input name="qty" type="text" id="qty" onchange="multiply()"/></td>
    <td><input name="amt" type="text" /></td>
    </tr><?php $i++; } ?>
</table>

</form>

</body>
</html>

rpv_sen

Junior Poster

178 posts since Mar 2011

Reputation Points: 18

Solved Threads: 16

1 Year Ago

You cannot have multiple tags with the same id. Your code will output multiple instances of and .

You should serialise them, like this:

<?php
	include("config.php");
?>
<script type=text/javascript>
function multiply(id){
var a;
var b;
var c;
a = document.getElementById("rate" + id).value;
b = document.getElementById("qty" + id).value;
document.getElementById("amt" + id).value = a * b;
}
</script>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>

</head>

<body>
<form action="" method="get" name="test">
<table width="800" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td align="center">S.No</td>
    <td align="center">Item Name</td>
    <td align="center">Item Code</td>
    <td height="30" align="center">Rate</td>
    <td align="center">QTY</td>
    <td align="center">Amount</td>
    </tr>
  <tr>
  <?php $desr="select * from site_rate where category_code='EWS001' AND sitename='Amber' order by item_code";
		//echo $desr;
	  	$r=mysql_query($desr,$conn);
	  	$i=1;
		while($m=mysql_fetch_array($r))
		{
			?>
    <td><?php echo $i; ?></td>
    <td><textarea name="cat_item" cols="25" rows="2"><?php echo $m['category_item'];?></textarea></td>
    <td><?php echo $m['item_code'];?></td>
    <td><input name="rate<?php echo $i; ?>" type="text" id="rate<?php echo $i; ?>"/></td>
    <td><input name="qty<?php echo $i; ?>" type="text" id="qty<?php echo $i; ?>" onchange="multiply(<?php echo $i; ?>)"/></td>
    <td><input name="amt<?php echo $i; ?>" type="text" id="amt<?php echo $i; ?>" /></td>
    </tr><?php $i++; } ?>
</table>

</form>

</body>
</html>

edwinhermann

Junior Poster

141 posts since Sep 2009

Reputation Points: 67

Solved Threads: 29

1 Year Ago

Thanks for your reply,

<td><input name="rate<?php echo $i; ?>" type="text" id="rate<?php echo $i; ?>"/></td>

Suppose if i use

<td><input name="rate[]" type="text" id="rate[]"/></td>

is it possible to get the value

rpv_sen

Junior Poster

178 posts since Mar 2011

Reputation Points: 18

Solved Threads: 16

1 Year Ago

Yes, you can for the name attribute but no not for the id attribute.
But in any event, the name attribute is never used because the form is never submitted; from what I can tell you are simply using input boxes to display information. The only reason to keep the name attribute is to produce HTML that is W3C compliant.

edwinhermann

Junior Poster

141 posts since Sep 2009

Reputation Points: 67

Solved Threads: 29

1 Year Ago

ok, i got output with your help.

Thanks for your interest and your valuable time

rpv_sen

Junior Poster

178 posts since Mar 2011

Reputation Points: 18