Code:

Break On
$array = 0,0,0,-1,0,-1
$flag = 'true'
For $n = 0 to Ubound($array)
If $array[$n] = -1
? 'Element ' + $n ' is -1'
Else
$flag = "false"
$n = Ubound($array)
EndIf
Next
? "All elements were -1 = " + $flag