‘contact seller’ button

Hi. I have a wordpress blog and I have a section which i have turned into a classified ads section. However, when someone posts an ad (i.e the seller) they have to leave their email or phone number as a way for someone to contact them.

I have noticed a lot of classified ads websites make it so the person browsing the website (i.e the person looking to buy) has to click on a ‘contact seller’ button and then fill out a form if they want to buy the item for sale.

I would like to implement this into my classifieds section as I think a lot of people looking to advertise would be reluctant to post an ad on my website as they have to show their phone number and email as a way for people to contact them, but i don’t know if there are any plugin’s or whatever that can help me do this.

So anyway my question to you folks is this: is there a way to implement this ‘contact seller’ button into my classified ads section which would make it so the buyer has to fill out a form – and thus making it so the seller does not have to show their email address or phone number on the ads they post.

OK thanks in advance – any help really would be appreciated.