Script to check if buyers email address match any of the account holder's

[vistamaster]

OK,

what a great idea I came up with... Is there a way to implement a bit of javascript, that would check the email address imput againts email addresses already in db for customer accounts?

when buyer is trying to buy, and if his entered email address match with the one in his account (the message comes up saying: you have an active account, please log in...)

Possible or not?

[malbro]

OK,

what a great idea I came up with... Is there a way to implement a bit of javascript, that would check the email address imput againts email addresses already in db for customer accounts?

when buyer is trying to buy, and if his entered email address match with the one in his account (the message comes up saying: you have an active account, please log in...)

Possible or not?

The files containing the user information on the web site are encoded so that will make it hard to deal with as an add-on.