Simple Javascript if else

[VVMustang]

Here's another one I'm having trouble making work.

I want to ask for a quantity and then fill in the fee based on the quantity answer.

If the quantity is 0 the fee will be 0 if the quantity is 4 the fee will be $40.

The error is "document.getElementId("EditRecordDirectory_Fee") is null

function calculate()

{

var quantity = parseFloat(document.getElementById("EditRecordDirectory_Quan").value);

var price = parseFloat(10);

var total = parseFloat(quantity * price);

if (quantity == 0)

{document.getElementById("EditRecordDirectory_Fee").value = 0;}

else

{document.getElementById("EditRecordDirectory_Fee").value = Math.round(total);}

}

document.getElementById("caspioform").onsubmit=calculate;

[Aariel]

I see that you have provided only one condition in if statement. i.e if (quantity == 0). What happens when quantity is Null?? Therefore, you have to check in a such way that the condition is satisfied if quantity is a number.

For example:

if(!isNaN(quantity))

{document.getElementById("EditRecordDirectory_Fee").value = 0;}

else

{document.getElementById("EditRecordDirectory_Fee").value = Math.round(total);}

hope it helps...

[londoncity]

I'd like to see why the "document.getElementId("EditRecordDirectory_Fee") returning Null. where did you put this JS code? make sure you put all your JS codes right before

[VVMustang]

Okay, I made the following modification (see below), with the same error (document.getElementBy....is null). The script is in the footer of the datapage.

function calculate_directory()

{

var quantity = parseFloat(document.getElementById("EditRecordDirectory_Quan").value);

var price = parseFloat(10);

var total = parseFloat(quantity * price);

if(!isNaN(quantity))

{document.getElementById("EditRecordDirectory_Fee").value = 0;}

else

{document.getElementById("EditRecordDirectory_Fee").value = Math.round(total);}

}

document.getElementById("caspioform").onsubmit=calculate_directory;