do we have any cck field which can do the tasks like username check.....

i need one cck field for example name of company, when the users add the company it should indicate that the name is already present ,,,
similar to user name check..

or else..

it gives the list of the company names (ajax search) when clicked on the name the rest to the details are filled automatically..

for example when i try to fill xxcvb company .. it gives me drop down list of the company names..if it is present when i click on the xxcvb company the rest of the fields like adress of the company is filled automatically...

or atleast it should indicate that company name is already present....

i have tried to google for this issue but dint find any....
pls guys help me