What's wrong with this macro ?

[ponch0]

This is my macro for Wyrms
1000 {Sd Wyrm} Target.Health400 Target.Shoot(3155)

What this macro does it's simple, shoots an SD when it's almost dead the Wyrm.
(Like that I avoid the Wyrm running.)


But I dont know what's wrong
Can somebody say me why ?
And maybe explain me what was my mistake please

TY