Big Oops!

I just thought I'd share with everyone a mistake I made that sent me on a goose chase on trying to find the culprit. In my DEFINE_PROGRAM section, I had a function being called that returned a value. Here's a snippet:

FOR (nLOOP=1;nLOOP<=LENGTH_ARRAY(dv_TP);nLOOP++)
{
	// Camera select feedback
	FOR(nLOOP1 = 1;nLOOP1<=LENGTH_ARRAY(nCAMERA_BTNS);nLOOP1++)
		[dv_TP[nLOOP],nCAMERA_BTNS[nLOOP1]] = (nCAM_SEL[nLOOP][fnGET_ROOM(nLOOP)] = nLOOP1)
}

Well, the panels can control multiple rooms so I need to know which room it was in. I could have used a simple room select variable, to keep track, but I was trying something new. Anyway... here's the function code:

DEFINE_FUNCTION INTEGER fnGET_ROOM			(* Get which room is being controlled */
(INTEGER nPANEL)
{
	FOR(nLOOP = 1; nLOOP <= 5; nLOOP++)
	{
		IF(nPNL_AV[nPANEL] == nAV_ZONE_MAP[nPANEL][nLOOP])
		{
			RETURN nLOOP;
			BREAK;
		}
	}
}

Can anyone spot the culprit right away? It took me a little bit to actually find it. I'm passing a variable into the function (nLOOP), and the variabled used for the FOR loop is ... nLOOP. I didn't even think about the variable getting used in multiple places at the "same" time. Well, here's the thing: it didn't cause any runtime errors, or anything like that. I was stuck! I couldn't even "pause" the program in debug. I figured it had to be something in the DEFINE_PROGRAM, so I started commenting things out and looking to see what could have messed up my program.

After about 10 minutes looking at it, it finally clicked! So to fix the problem I created a STACK_VAR in the begining of the function and used that for the FOR loop. A stupid mistake on my part, but I just thought I'd share my embarassing moment in programming in hopes that others will at least learn from my mistake. Talk about a BIG OOPS!