Attempting to write a check for a login script to see if the username is available.

Would the best way to write this query be to check

if isset(!_POST[]) for both values (nick and pass)

then connect to database

WHERE the mysql database for the usernick requested

return the user id if the usernick exists

evaluate if isset($id) to see if the user name is taken

and use that to continue to creating an entry

Does this logically sound like a method to check for login without using excessive code

sorry for not posting the code, it is on another computer and this computer is locked down by my administrator at work...

Also, is there another way to evaluate if a value exists in the database?

For instance, instead of setting $id to the return value of the mysql database can i just ping the mysql database for the information and have it return a Boolean result so I am not putting out any user information.

Thanks, Matt