Facing problem with changing the display amount on change

[sandhya]

Hi all,

      I have a billing form. I managed to display the total amount by collecting and calculating the values from database. Now I have a text box named discount on the side of amount display. Now I have to subtact the enterd discount from total amount and display the total amount on change. How can i do it now. Anybody help me.

[dsaba]

if discount is a percentage, then use arithmetic.

 

$discount = .10;

$oldTotal = 233;

$updatedTotal = $oldTotal - ($oldTotal * $discount);

[priti]

javascript solution would be somethinglike this....

 

<input type="text" name="total" value="10"> -<input type="text" name="discount" value="10" onChange="calculateBillamoutn(this.form)">=<input type="text" name="billAmount" value="">

 

in javascript

 

function calculateBillamoutn(frm)

{

var price=frm.total.value;

var discout=frm.discount.value;

 

frm.billAmount.value=price-disocunt;

 

}

 

 

[sandhya]

Thanks, but I con't use the text box here for total(i mean netamount) . And already calculated the items total value and assaigned to the variable $total. using this variable i've to do it. At first the netamount should be displayed and on changing the discount value, the netamount should be refreshed eveytime.

[priti]

if you net amount is in label then you can do a trick keep in in <p id="netamount"> or <div id="netamount">  and then you can use it the way you want.