Thank you for your question. I looked on my default install of VirtueMart, and was unable to locate a Whitebox. Could you please provide more information, such as a link to the Whitebox you are using, or your website's URL?
If you have any further questions, feel free to post them below.
I mean something: http://postimg.org/image/vl2k22ot5/, you can see, here is virtuemart demo page, http://demo.virtuemart.net/, if you clic on first product "Add to Cart" you will see the lightbox, thanke you for your help.
Thank you for the question! It appears that you want to change the text in the lightbox being generated from Virtuemart. Is this correct? If so, you may want to review this post. It mentions that the text is related to the title="" attribute inside the link element. There are also some other posts that talk about making changes to the lightbox in a template, but I'm not sure that these would apply to you. Please review the post, and if you continue to have questions, please let us know.