Image Transparacy, not working help! :D

[Asheh]

					$border_src= ImageCreateFromPNG($border_str);
				$border_img_w = ImageSX($border_src);
				$border_img_h = ImageSY($border_src);
				$border_image = ImageCreateTrueColor($border_img_w, $border_img_h);
				imagecopy($border_image, $border_src, 0,0,0,0, $border_img_w, $border_img_h);
				imagedestroy($border_src);

				$imgwhite = imagecolorexact($border_image, 255,255,255);
				imagecolortransparent($border_image, $imgwhite);
				imagecopymerge ($base_image, $border_image, 0, 0, 0, 0, $border_img_w, $border_img_h, 100);
				ImageDestroy($border_image); //finished with the border  image, destroy.

 

I have a png image which has a border, and a base image.

 

The border should only copy over the border to the base image, it does this but it makes the transparent bits black.

 

Im really stuck here ive looked everywhere for a solution, can anyone help?