(Perth)  --  There's still no sign of that missing airliner from Malaysia.  Malaysian Airlines Flight 370 is believed to have gone down somewhere over the Indian Ocean last month, but there's still no sign of wreckage.  Officials believe all 239 people on board were lost.  The focus of the massive search has shifted since the plane first disappeared from radar.  More than a dozen countries are devoting manpower and equipment in hopes of finding any sign of the missing Boeing 777.  

Experts fear that the batteries transmitting a signal from the plane's black box will soon fail.  The device is designed to ping for 30 days but the plane disappeared more than three weeks ago.