AJAX to check the login name exists or not

[fatima18]

i have a login box...when the user starts typing.. i want to check whether the LOGIN NAME entered exists in the database or not... if the login name is exist i am going to set the login button active... if it doesnot exist i am going to set the login button deactive... offcourse i am going to need AJAX to perform my mySQL via PHP tough i don't know how it will be done...lets say this is my query \[code\]<?php $result = mysql_query("SELECT * FROM accounts WHERE name='mytextboxvalue'"); ?>\[/code\]how to do it