Few jquery errors , Attention J Query Gurus, invalid label

Attention J Query Gurus J Query gurus can you put some light on this matter please?

I am using J Query method for Ajax calls in my asp.net projects

contentType:”application/json; charset=utf-8″,

In above I am using “datatype”  as small characters, its working 100%  for me in one project  also i am not uisng “response.d” when I am using eval() method to convert it from json string to array. i was using var myObject= eval(“(”+ eval(response)+ “)”);

I creatd a second project and used same i.e (“datatype” as small characters) but it started throwing errors.

Then I switched back to proper syntax ie. “dataType” using “T” as caps and this line started throwing errors var myObject= eval(“(”+ eval(response)+ “)”);

“invalid label” after speding sometime i came to know that I need to use var myObject= eval(“(”+ response.d+ “)”); when i used response.d it started working.

Does anyone else experienced this type of problem in J query.