jQuery.extend = jQuery.fn.extend = function() {

     var src, copyIsArray, copy, name, options, clone,

         target = arguments[ 0 ] || {},

         i = 1,

         length = arguments.length,

         deep = false;

     // Handle a deep copy situation

     if ( typeof target === "boolean" ) {

         deep = target;

         // skip the boolean and the target

         target = arguments[ i ] || {};

         i++;

     }

     // Handle case when target is a string or something (possible in deep copy)

     if ( typeof target !== "object" && !jQuery.isFunction( target ) ) {

         target = {};

     }

     // extend jQuery itself if only one argument is passed

     if ( i === length ) {

         target = this;

         i--;

     }

     for ( ; i < length; i++ ) {

         // Only deal with non-null/undefined values

         if ( ( options = arguments[ i ] ) != null ) {

             // Extend the base object

             for ( name in options ) {

                 src = target[ name ];

                 copy = options[ name ];

                 // Prevent never-ending loop

                 if ( target === copy ) {

                     continue;

                 }

                 // Recurse if we're merging plain objects or arrays

                 if ( deep && copy && ( jQuery.isPlainObject( copy ) ||

                     ( copyIsArray = jQuery.isArray( copy ) ) ) ) {

                     if ( copyIsArray ) {

                         copyIsArray = false;

                         clone = src && jQuery.isArray( src ) ? src : [];

                     } else {

                         clone = src && jQuery.isPlainObject( src ) ? src : {};

                     }

                     // Never move original objects, clone them

                     target[ name ] = jQuery.extend( deep, clone, copy );

                 // Don't bring in undefined values

                 } else if ( copy !== undefined ) {

                     target[ name ] = copy;

                 }

             }

         }

     }

     // Return the modified object

     return target;

 };