[kde-linux] Javascript statement: visible=(obj.style.display=="block"); problem in Konqueror 3.4.2

[Randy Kramer]

I'm having trouble with a javascript program I've copied out of a book (to 
continue my experimentation/learning).  The program works fine in opera, but 
gives me a "Type Error -- Null Value" at the following line (in Konqueror 
3.4.2):

visible=(obj.style.display=="block");

(In the book that I copied the program from, it didn't have the trailing 
semicolon, but I added that and have tried it both ways.)

The lines preceding that line are:

function Toggle(e) {
  if (!document.getElementById) return;
  if (!e) var e = window.event;
  whichlink = (e.target) ? e.target.id : e.srcElement.id;
  obj=document.getElementById(whichlink+"menu");
  visible=(obj.style.display=="block");

I've done a little experimenting, trying things like:

obj.style.display="block";
obj.style.display="inline";
obj.style.display="none";
obj.style.display="0";

...but all with the same error and message.

In another trial program (which I wrote myself), I used statements like the 
following with no problem:

<span id="H11" !--onclick show spans L1 and H2--
onclick='document.getElementById("L11").style.display="block"; 
document.getElementById("H1121").style.display="block"'>

So, then I tried a statement like the following, but ended up with the same 
"Type Error -- Null Value":

visible=(document.getElementById(whichlink+"menu").style.display=="block");

Randy Kramer