Goal:  

Every time you make a input data in the textbox (named txtInputData) you send the data to the server automatically and you compare the input data to the database's table.  

In the end you retrieve a true or false if the data of txtInputData is the same from the database. 

Problem:  

I don't know how to make the textbox to send the data to the server with json automatically in every time when you make a input data. 

I don't know where to start? It sounds to be more complicated than I thought. 

Info:  

\*Jquery with Json is strongly recommended.