Thank you Tom
I used the script from the following link below
then I make it executable and I opened a terminal in the in directory of the script and then used the command " --verbose" it worked fine on ubuntu 15.04 64bit but the same process did NOT go well on ubuntu14.04 64 bit while during installation I did NOT receive any errors, about searching , I opened the dashboard in ubuntu and searched for once GRC and the other time I searched for GNUradio , but nothing was found , further I ran the command "gnuradio-companion" in the terminal then I received a an error telling that gnuradio is not installed use sudo apt-get install gnuradio-companion to install it ,
Thanks
Alfred