nesting picture boxes and their parent function

I have inserted a picture box inside which there is another smaller picture box. I have made the back color of the smaller picturebox to transparent, for this to work properly i have run the following code in form1_load.
"SmallerPictureBox.Parent = BiggerPictureBox"

And it works fine.
But now i need to insert a small label inside the SmallerPictureBox and make the back color of the label also transparent. to do that i used this code:
"label.Parent = SmallerPictureBox"

But now this is not working and the label is not being seen at all.
And i have put these 2 lines of code in this same order also.
Wat shud i do so that the label is seen on the SmallerPictureBox and also be transparent??
Please Help.