XOR and Blowfish Xryption help!

Why doesn't this work?

Text$ 	= "¤Top Secret 2[#]17 Mesage¤" '"fish"
Password$	= "blowfish"

Print "Data: "+Text
Print "Key : "+Password

EncryptString( Text, Password )

Print "After Encryption.. "
Print "Data: "+Text
Print "________________"

EncryptString( Text, Password )

Print "After Decryption.. "
Print "Data: "+Text
Print "________________"

Function EncryptString( Data$ Var, Key$ )
	Local x,i,crypt$
	For i = 0 Until Data.length
	
		'Print Chr( Key[x])+"   X: "+x'Chr( Data[i] )
		
		Crypt:+ Chr( Data[i] ~ Key[x] )
		x:+1
		If x >= Key.length X=0
	Next	
	Data$ = Crypt$
EndFunction

It works with a plain text key..