Image src

JavaScript
1

Trying to figure out where i’m going wrong here…

function incdot(fname,val) {
   var newval = parseInt(document.getElementById(fname).value) + val;
   var imgname = fname + "img";
  if(newval <= 5 && newval >= 0) {
     document.getElementsByName(imgname).src = fdot[newval].src;
	 document.getElementsByName(fname).value = newval;
  }
}

In IE, newval gets set correctly. fdot[newval].src correctly returns a string.
The image source doesnt change. No errors are thrown by IE’s debugger
Chrome’s debugger and FF’s error console decides that document.getElementById(fname) is null, and fails immediately.

2

getElementsByName() returns an array of objects.

Which index in that array are you assigning fdot[newval].src to the object’s src?

3

okay… that makes sense… was just tripping me up because there was only one such element…

but why does FF and Chrome think document.getElementById(fname) is null?

4

ok, you need to do some basic debugging.

Just above

 
   [COLOR=#003366][B]var[/B][/COLOR] newval = parseInt[COLOR=#66cc66]([/COLOR]document.[COLOR=#006600]getElementById[/COLOR][COLOR=#66cc66]([/COLOR]fname[COLOR=#66cc66])[/COLOR].[COLOR=#006600]value[/COLOR][COLOR=#66cc66])[/COLOR] + val;

insert

 
alert(fname);

then make sure you have an element in your html with an id equal to the output of the alert().

I suspect you won’t have and that is why FF and Chrome are tripping up. I think some browsers will take the value of the name attribute as the id if the id attribute does not exist.

5

I can’t find the thread where I thought I read that some browsers use the element name as the id where the id is missing. Maybe I was wrong.

Anyway, I assume the debugging I suggested has helped you fix your problem by now.