Need to pass more than 50 inputs to JSON WebMethod

Hi,
I have aspx page with more than 50 input fields. 
I want to insert input values in table and would like to use JSON (And using WebMethod declared in code behind page to insert in DB), But instead of passing each and every field in 
data: '{Key1:"' + Value1 + '", Key2:"' + Value2 + '", Key3:"Value3" }'
Is it possible to pass form as DATA to JSON WebMethod and this WebMethod will access form data and use it for insert.

Please advice.  Or Any other way to eliminate passing each key/value in DATA ......
Waiting for inputs ....