is this a good idea or not?

Hi, I was wondering whether this use of SetEnv() / GetEnv() is safe or not:

Graphics 800,600,32,2
SeedRnd MilliSecs()
SetBuffer BackBuffer()

;variables
Global scrw = GraphicsWidth()
Global scrh = GraphicsHeight()
Global age = 10

Type bug
	Field x,y,n$,c
End Type

;setup

;main loop
While Not KeyHit(1)
Cls

Color 255,255,255
Rect 100,100,scrw-200,scrh-200,0

For b.bug = Each bug
	Color b\c,127+Sin(b\x*10)*127,127+Sin(b\y*10)*127
	Rect b\x-20,b\y-20,41,41,0
	Color 255,255,255
	Text b\x,b\y,b\n$,1,1
	b\x=b\x+Rnd(-5,5)
	b\y=b\y+Rnd(-5,5)
	If b\x<120 Then b\x=120
	If b\y<120 Then b\y=120
	If b\x>scrw-120 Then b\x=scrw-120
	If b\y>scrh-120 Then b\y=scrh-120
Next

Locate 0,0
Print "<Insert> to Make bug"
Print "<Delete> To kill bug"
If KeyHit(210) Then FlushKeys():makebug(Input("Make Name : ")):FlushKeys()
If KeyHit(211) Then FlushKeys():killbug(Input("Kill Name : ")):FlushKeys()

Flip
Wend
End

;functions
Function makebug(name$)
	If name$<>"" And Object.bug(GetEnv("bug_"+name$))=Null
		b.bug = New bug
		b\x = Rnd(100,scrw-100)
		b\y = Rnd(100,scrh-100)
		b\n$ = name$
		b\c = Rnd(0,255)
		SetEnv "bug_"+name$,Handle(b)
	EndIf
End Function

Function killbug(name$)
	b.bug = Object.bug(GetEnv("bug_"+name$))
	If b.bug <> Null
		Delete b
	EndIf
End Function

thanks