While we're on the free advice tour anyway, ask your friend if it is ok to put a link on your creation to your own page.
Just a simple text link at the bottom that reads 'pages designed by yourname'. That should go a long way to making sure that people can verify your claims.
In return, from your portfolio you will link to their site, a small screenshot for each customer that you've served will do. Seeing the backlink on those pages is the proof that you are really the designer of those pages.
he wouldnt want that because he runs a graphic design business and it would look bad if his own site says its designed by someone else.
btw, if anyone actually needs proof that i did in fact design it, just contact him through his site. I'll let him know that I posted on HN as anonymous512
Hm. Ok, so your friend is probably a good reason to take to heart the rest of the comments here, that is exactly why people want to see proof. Too many people out there claim they can do stuff when in fact all they do is outsource it to the lowest bidder at a ridiculous markup.
Still, you will need to make a page that lists your accomplishments, in this particular case you won't be able to put up a link, but if you've been doing this for a while you should be able to go through your harddisk to find a couple of examples of what it is that you can do.
I understand that you are in Bangladesh, that should give you an excellent position from a competitive point of view, people from the 'third world' can undercut people from the west in ways that there simply is no competing with.
At the same time, there is a - healthy - amount of skepticism with respect to the originality of designs from people that there is no face to face contact with, it is all too easy to misdirect potential customers by showing them the work of somebody else.
Just a simple text link at the bottom that reads 'pages designed by yourname'. That should go a long way to making sure that people can verify your claims.
In return, from your portfolio you will link to their site, a small screenshot for each customer that you've served will do. Seeing the backlink on those pages is the proof that you are really the designer of those pages.