Non-existent pacakge
sabyasachi@sabyasachi-Inspiron-N5110:~/catkin_ws$ rospack depends1 beginner_tutorials [rospack] Error: package 'beginner_tutorials' depends on non-existent package 'std_mshs' and rosdep claims that it is not a system dependency. Check the ROS_PACKAGE_PATH or try calling 'rosdep update'
how to fix this problem, i am comepletely new to ubuntu(14.04) and ros ?