I have this code in my wordpress template
<a onclick="get_project_data(<?php echo get_the_ID(); ?>)"><img src="<?php echo wp_get_attachment_url( $logoimg_id ); ?>" onmouseover="this.src=\'<?php echo wp_get_attachment_url( $logoimg_id+b ); ?>';" onmouseout="this.src=\'<?php echo wp_get_attachment_url( $logoimg_id ); ?>';"/></a>
But it doesn't work, I need to show a full colour image and a black and white with on over, the thing is that I need to do this automatically so I will upload to my server photo.jpg and photob.jpg (black and white) css is not an option.
Thank you