It's less secure than having the user fill out the information in a posted form, but you can include the username and password values in the link itself, as in:
Fill in the ... with valid username and password values.
Your login code will then have to read query string parameters rather than just form parameters. Don't worry though, in many environments the same code reads both.
OK, please look here www.theroyalmove.com/clients to understand my question. As you can see at the bottom of that page are pictures of houses. When a client clicks on their house, they can login to see more pictures. When I create a page like that, I always send out invitations to the client and their family or friends. In that email I would like to have a link, a special link, that when they click it, it fills in the username and password automatic- then they can click remember and never have to worry about it. In the email it says what username and password is, it's just a pain to go back to the email rememeber username, go back and look at password... etc. I just thought it would be easier the other way. Now the probably biggest question is: Is there such script/link?