Open a new checkbox / window to select a specific value

Question

I have a list of users that are dynamically generated.

$sql0="SELECT * FROM users";
$result0 = mysqli_query($con,$sql0);
if(mysqli_num_rows($result0)>0)
    {
        while($row0=mysqli_fetch_assoc($result0))
            {   
                echo $row0['name'];
                echo "<br>";
            }
    }

O / p will contain a list of users, for example:

user_one
user_two
user_three

What I want is that if I click on one user from the above list, the chat window should be open (as is done on many sites at present). I have a window created here @ fiddle . but what I cannot do is that

I want to transfer the user ID of the selected user to this new window and display data related to this selected user, such as name, image, etc.

And I want to fix the chat field at the end of the screen, as it is done in fb so that the user can open several mailboxes

- ,

Answer 1

css : -

.panel-primary 
{
    bottom:0;
    position:fixed;
}

.