String is undefined in jquery-1.7.1.min.js

String is undefined in jquery-1.7.1.min.js

Hi Team,
 
I have included jquery-1.7.1.min.js file in my aspx page .
 
After executing some javascript functions, the call is going into jquery-1.7.1.min.js file
 
And it throws me following error "JavaScript run time error :String is undefined"
 
I have changed to jquery-1.10.2.min.js file as well, then I am getting new date() is undefined.
 
Thanks & Regards
Sai krishna