FindFirstChild (Function)

FindFirstChild( String Name, Bool recursive )
Returns	Instance found object
Description:	Returns the first child found with a name of Name. Returns nil if no such child exists.

Example

function OnTouched(hit)
 brick = hit.Parent:FindFirstChild("Torso")
 if (brick ~= nil) then
  brick.BrickColor = BrickColor.new(1)
 end
end

script.Parent.Touched:connect(OnTouched)

It can also be used to find objects with spaces

function OnTouched(hit)
 brick = hit.Parent:FindFirstChild("Left Leg")
 if (brick ~= nil) then
  brick.BrickColor = BrickColor.new(1)
 end
end

script.Parent.Touched:connect(OnTouched)