Stopping a Command

I made this function…

[lua]
hook.Add(“Think”, “Test”, function()

for k,v in pairs(ents.FindInSphere( Vector(-2301.836914, -50.902897, -131.968750), 42)) do
if v and v:IsValid() and v:IsPlayer() then

v:ChatPrint(“Test”)
end

end

end)
[/lua]

Now, whenever you go within the area I set you get spammed. Well, v:ChatPrint keeps getting ran, nothing is stopping it.

How do I code it so something stops v:ChatPrint and only makes it run once?

If thats not possible can it be set to run every 15 seconds?

[lua]
hook.Add(“Think”, “Test”, function()
if not( NextTime ) then NextTime = CurTime() end
if( NextTime < CurTime() ) then
NextTime = CurTime() + 15
for k,v in pairs(ents.FindInSphere( Vector(-2301.836914, -50.902897, -131.968750), 42)) do
if v and v:IsValid() and v:IsPlayer() then

     v:ChatPrint("Test")  
  end  

end  

end

end)
[/lua]