A method of determining operational status of a handheld wireless communication device capable of executing server-side applications, the server-side applications being provided on a server which sends data flow messages to the handheld wireless communication device, said dataflow messages containing application data for use by a virtual machine executing at said handheld wireless communication device, the method comprising: sending, from the server to the handheld wireless communication device, an application definition file for defining functionality associated with a server-side application, the application definition file for use by the virtual machine of the wireless communication device, the application definition file further defining a format of the data flow messages to be transmitted between the server-side application and the virtual machine; sending a ping message to said handheld wireless communication device soliciting operational status information from the handheld wireless communication device, wherein the ping message soliciting operational status information is selectively (i) of a first type, requesting whether the handheld wireless communication device is active, or (ii) of a second type, requesting diagnostic information about the virtual machine of the handheld wireless communication device; and receiving a response message from said handheld wireless communication device containing the operational status information indicative of the operational status of the handheld wireless communication device; wherein the operational status information comprises, respectively, if the handheld wireless communication device is active, (iii) an indication that it is active, or (iv) diagnostic information about the virtual machine of the handheld wireless communication device, the diagnostic information comprising a quantity of data flow messages queued by the virtual machine. sending, from the server to the handheld wireless communication device, an application definition file for defining functionality associated with a server-side application, the application definition file for use by the virtual machine of the wireless communication device, the application definition file further defining a format of the data flow messages to be transmitted between the server-side application and the virtual machine; sending a ping message to said handheld wireless communication device soliciting operational status information from the handheld wireless communication device, wherein the ping message soliciting operational status information is selectively (i) of a first type, requesting whether the handheld wireless communication device is active, or (ii) of a second type, requesting diagnostic information about the virtual machine of the handheld wireless communication device; and receiving a response message from said handheld wireless communication device containing the operational status information indicative of the operational status of the handheld wireless communication device; wherein the operational status information comprises, respectively, if the handheld wireless communication device is active, (iii) an indication that it is active, or (iv) diagnostic information about the virtual machine of the handheld wireless communication device, the diagnostic information comprising a quantity of data flow messages queued by the virtual machine.