apex.jQuery.ajax({
			  dataType: type,
			  type: "post",
			  url: "wwv_flow.show",
			  traditional: true,
			  data: {
					p_request: "NATIVE=' ||
				   apex_plugin.get_ajax_identifier || '",
					p_flow_id: $v("pFlowId"),
					p_flow_step_id: $v("pFlowStepId"),
					p_instance: $v("pInstance"),
					x01:px01,
					x02:px02
				
				},
				success: function(textData) {
					callback(textData);									 
				},
				error: function(jqXHR, textStatus, errorThrown) {
				    callbackE(jqXHR);   <-- суда должен попасть                
				}
		});

error
Type: Function( jqXHR jqXHR, String textStatus, String errorThrown )
A function to be called if the request fails.