check if email already in use

[abs0lut]

I have an input field
<input type="text" name="email" id="email">
an alert will popup if the user entered an email that is already in use/ exists in database.
is it possible in javascript? could you please help me?

[magicyte]

You cannot access a database with JavaScript. However, you could have the user submit it with PHP so that the website can see if the e-mail is equivalent to yet another, at which point you can use javascript to alert the user.

-magicyte

[abs0lut]

how about ajax? I don't want to loose the value of the input fields which entered by the user.