new this function to 'datatype' of jqgrid options, this will sync between Backbone collection and jqGrid

backbone-jqgrid-reader.js

  var BackboneJqGridReader = function(colleciton, grid) {
		return function(postdata) {
			var submitData = _.extend({}, postdata);

			Backbone.sync("read", colleciton, {
				attrs: submitData,
				cache: false,
				contentType: "application/json",
				processData: false,
				type: "POST",
				success: function(data) {
					colleciton.reset(data.gridModel);
					grid.setGridParam({
  					lastpage: data.total,
						page: data.page,
						records: data.records
					});
					grid.each(function() {  
			        	if (this.grid) this.updatepager();  
			       });
				}
			});
		};
	};