Don’t need to define thisTransform, all you need to use is ‘transform’ for that. You also need to use var… Just to clean things up, I’d make a Generic List instead of array.
#pragma strict
import System.Collections.Generic;
var children : List.<Transform> = new List.<Transform>();
function Start ()
{
for(var t in transform)
children.Add(t);
for(var c in children)
print(c.name);
}