link to the login page with prefilled username and passwords

Hi. I would like to create a link to the login page with prefilled username and password because I have many wordpress sites and would like to access them more easily.
for example: http://www.mywordpresssite.com/wp-login?username=siteadmin?password=1234
when I follow the link to the login page, I will see that the username and passwords form fields are already filled with the attributes I gave in the link
Thanks.