Simply end

If a condition isn't met how to I end the script and take it back to defaul?

Well, that depends on what you mean by "end". By their very nature, scripts aren't designed to "end"; they just run out of things to do.

If you want one to just restart, use llResetScript();

If you want the script to go away completely from the object, use llRemoveInventory(llGetScriptName());

I suppose the script could also set itself not running with llSetScriptState();

Lots of ways to do something akin to "ending", just depends on why and what you want to do.

Thanks - as you can see I'm a little thick on the ground here - you have answered the question - reset is what I'm after.

Tarak