How to fetch text from "alt. text" in images

Hi!

I’m trying to fetch the text from what is written in the alternate text field of an image.

What I try to achive with it is this: I have an image gallery on my page, when I click the images it opens them up in a lightbox. But instead, I will link each image to a post I have written about them. So I thought I could enter url to each post in the images alternate text field, and then have the code where the link is made get that text. This way I can enter a different url for each image.

But I am a coding noob and I need help.

Here is the code I try to alter:

foreach($all_photo_arr as $photo)
{
	$full_image_url = wp_get_attachment_image_src( $photo->ID, 'full' );
	$small_image_url = wp_get_attachment_image_src( $photo->ID, 'large' );

	echo '<img>';
	echo '<src>'.$small_image_url[0].'</src>';
	echo '<link>'.$full_image_url[0].'</link>';
	echo '<title></title>';
	echo '<caption></caption>';
	echo '</img>';
}

I guess that the string to the “alternate text” field has to be put in somehow in between the <link> tags.

What do I put in between there to make it work? =)