I need help please

Hello,
I thought that I could get this to work, I've stumbled around, to me it looked right but it doesn't work. Can some nice person please look at this code and tell me where I went wrong.
Thank you all so very much.

default
{
state_entry()
{
key id = llGetOwner();
llListen(3,"","","");
}
    changed(integer change)
    {
        if (change & 128)
        {
            llResetScript();
        }
  } 
listen(integer channel,string name,key id,string message)
{
if (message == "stop")
{
    llLoopSound ("j3turbo", 0.0); // I want to turn the sound off, this way seems to work. LOL, its hard not being a coder
    llSetColor(<0.5,0.5,0.5>, ALL_SIDES);
    llSetPrimitiveParams([PRIM_MATERIAL, PRIM_MATERIAL_METAL]);
  }
{if (message == "start")
llLoopSound ("j4turbo", 20.0);
llSetColor(<1,0,0>, ALL_SIDES);
llSetPrimitiveParams([PRIM_MATERIAL, PRIM_MATERIAL_LIGHT]);
}
}
}

This should do what you want. No idea what you were attempting with the change event, so I took it out.

default
{
    state_entry()
    {
        key id = llGetOwner();
        llListen(3,"","","");
    }
    
    listen(integer channel,string name,key id,string message)
    {
        if (message == "stop")
        {
            llStopSound(); // I want to turn the sound off, this way seems to work. LOL, its hard not being a coder
            llSetColor(<0.5,0.5,0.5>, ALL_SIDES);
            llSetPrimitiveParams([PRIM_MATERIAL, PRIM_MATERIAL_METAL]);
        }
        
        if (message == "start")
        {
            llLoopSound ("j4turbo", 1);
            llSetColor(<1,0,0>, ALL_SIDES);
            llSetPrimitiveParams([PRIM_MATERIAL, PRIM_MATERIAL_LIGHT]);
         }
    }
} 

In the state_entry() event, you set some variable called "id", but you don't use it anywhere ?

IIRC, that changed event is apparently an undocumented constant that stands for "changed owner".

When you say the script doesn't work... what doesn't work? What do you want it to do? Are you typing /3 start and /3 stop to try and activate it?

The color change and the change from metal to light, and back didn't work.

I think I see a potential bug. Try this:

default
{
    state_entry()
    {
        key id = llGetOwner();
        llListen(3,"",id,"");
    }
    
    listen(integer channel,string name,key id,string message)
    {
        if (message == "stop")
        {
            llStopSound(); // I want to turn the sound off, this way seems to work. LOL, its hard not being a coder
            llSetColor(<0.5,0.5,0.5>, ALL_SIDES);
            llSetPrimitiveParams([PRIM_MATERIAL, PRIM_MATERIAL_METAL]);
        }
        
        if (message == "start")
        {
            llLoopSound ("j4turbo", 1);
            llSetColor(<1,0,0>, ALL_SIDES);
            llSetPrimitiveParams([PRIM_MATERIAL, PRIM_MATERIAL_LIGHT]);
         }
    }
}

Or this:

default
{
    state_entry()
    {
        key id = llGetOwner();
        llListen(3,"",NULL_KEY,"");
    }
    
    listen(integer channel,string name,key id,string message)
    {
        if (message == "stop")
        {
            llStopSound(); // I want to turn the sound off, this way seems to work. LOL, its hard not being a coder
            llSetColor(<0.5,0.5,0.5>, ALL_SIDES);
            llSetPrimitiveParams([PRIM_MATERIAL, PRIM_MATERIAL_METAL]);
        }
        
        if (message == "start")
        {
            llLoopSound ("j4turbo", 1);
            llSetColor(<1,0,0>, ALL_SIDES);
            llSetPrimitiveParams([PRIM_MATERIAL, PRIM_MATERIAL_LIGHT]);
         }
    }
}

The first version should listen only to the owner, the second should listen to anyone. And make sure you're issuing the commands on channel 3, i.e. type "/3 start" (without the quotes).

The reason it wouldn't work in the orignal was there was a bracket issue. I fixed that. The script worked fine after that.

If you want to set it up to allow only the owner to activate the script, and you intend to transfer it to other people then go ahead and put the changed owner code back in. Otherwise you don't need it and it wasn't the problem. I just removed it to simplfy the issue and forgot to take out the variable in state entry.

Ah. Thanks. I didn't realize you'd changed something in the script besides the llStopSound, and I didn't know if "" worked as a null key. Sorry about that

Thank you all so very much for fixing this. I was pulling my hair out trying to get it to work.
Thank you