Re: [LUG] Some help with javascript & firefox

["Steven Cote" <steven.cote@xxxxxxxxx>]

now I get
parseint is not defined
http://www.minionsbandb.co.uk/oldsplitaddtable.html
Line 106

Woops, that's my fault. This is what I get for typing it out instead of cut/pasting it. The function is parseInt()
Note, the capital 'I'. It's case sensitive. Check this link for the ins and outs of it:
http://www.w3schools.com/jsref/jsref_parseInt.asp

> alert("vat_low" + rowNum);
> alert("vat_low" + rowNum.value);
> <!-- alert (parseint(document.splitfm.vat_low.value)); -->
> alert (newTxt2.ID)
>
> the parseint bit halts the script.
> can I use the ID ? 
> is there an ID .value?
> If I do an alert for this it says Undefined?

You're going in the wrong direction with this stuff.


Let's go back to my block edited for error (and the suggestion by Julian), and I'll explain what exactly it's doing.

1  var sum = 0;
2  var vat_low;
3  for( var i = 0; i <= rowNum; i++ ) {
4     vat_low = 'sum += parseInt( document.splitfm.vat_low' + i + '.value )';
5     eval(vat_low);
6  }
7

All the magic is happening on line 4 and 5. Basically, we've got a loop that goes around once for every table row you've added. On line 4, I'm saving a string into the variable vat_low by concatenating a literal string with the value in i with a second literal string. So, on the first iteration, the value of vat_low is:
"sum += parseInt( document.splitfm.vat_low3.value )"

Then on line 5, that string is executed as if it were a line of _javascript_.

So, just to break that line down: the "document.valt_low3.value" gets the value from the input box as we wanted. Now, the problem there is that it's treated as a string unless we specifically make it an integer, so we pass it to the parseInt() function. This returns the value of that input box as an integer. Then that value is added to the variable 'sum' as was neatly explained by Julian.

So, the net result is to loop through each added row and to add the value of the low_vat input box into a variable that after the loop can be assigned wherever you'd like (I'm assuming document.splitfm.low_vattot.value).

Hopefully that helps and doesn't just make everything worse for you.

Have a look at the site http://www.w3schools.com/jsref/
It's got a lot of good stuff on it and should help you out in your endeavors. And for Firebug, have a look at breakpoints and how to use them. You'll never use alert() to debug ever again once you get the hang of it (http://www.getfirebug.com/js.html).

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