Need some help with a visitor list maker

Hello, Im Baaaack lol

Ok Im in the very early stages of a security system project that requires a list of the 12 most recent visitors to a location. So I created a collision based visitor list maker no problem there. However I need this visitor list to store both the visitors name and Key. I need the name to be able to display in an llDialog a little later, and I need the key to be able to pass to the land functions.

What I have seems to be working correctly so far except for some reason my list containing the keys is always returning an empty value. What am I doing wrong? Any assistance to make it more efficient would also be helpful.

list visitor_list;
list key_list;


integer isNameOnList( string name )
{
	integer len = llGetListLength( visitor_list );
	integer i;
	for( i = 0; i < len; i++ )
	{
		if( llList2String(visitor_list, i) == name )
		{
			return TRUE;
		}
	}
	return FALSE;
}


default
{
	state_entry()
	{

		llVolumeDetect(TRUE);
	}

	collision_start( integer number_detected )
	{
		integer i;
		for( i = 0; i < number_detected; i++ )
		{
			if( llDetectedType( i ) & AGENT )
			{
				//if( llDetectedKey( i ) != llGetOwner() )  //commented out for testing
				//   {                                      //commented out for testing

				string detected_name = llDetectedName( i );
				string detected_key = llDetectedKey(i);

				llOwnerSay(detected_name + " added");//Debug
				llOwnerSay(detected_key + " added");//debug


				if( isNameOnList( detected_name ) == FALSE )
				{

					visitor_list = llList2List( visitor_list + detected_name, -12, -1 );


					key_list = llList2List( key_list + detected_key, -12, -1 );



				}
				// }                                           //commented out for testing

			}
		}
	}

	touch_start(integer total_number) //For testing purposes
	{
		integer i;
		integer length = llGetListLength(visitor_list);
		string visitor;
		string visitor_key;




		for( i = 0; i < length; i++)

			visitor = llList2String(visitor_list,i);
		visitor_key = llList2String(key_list,i);

		llOwnerSay(visitor + " = " + visitor_key );
			}

}

change this:
key_list = llList2List( key_list + detected_key, -12, -1 );
to this
key_list = llList2List( key_list + [detected_key], -12, -1 );
it might do the trick
or this: (since detected_key is declared a string)
key_list = llList2List( key_list + [(key)detected_key], -12, -1 );

THanks for the help, but neither of those worked.

Try putting a statement like this in your 'collision_start' handler to make sure you're getting there:

llOwnerSay("DEBUG - defaut/collision_start, point A";

If you get there, put one somewhere else, like in the conditionals where you add an entry. You might even want to spit out a copy of one or both of your lists at the point where you add to them:

llOwnerSay("DEBUG - default/collision_start, point B; visitor added; visitor_list = "+llList2CSV(visitor_list));

That should help you start to track down the issue. Welcome to the world of printf type debugging.