'inst.PathName' is null or not an object error

anyone tell me why this snippet of code gives the error 'inst.PathName' is
null or not an object



//extract just the file name
var arrExe = inst.PathName.split("\\");
var stateval = GetPropValue(svcs, "State", State);
var startmodeval = GetPropValue(svcs, "StartMode", StartMode);
oService.setValues(Name, arrExe[arrExe.length-1], stateval,
startmodeval);