when i run "virt-manager" it gives "RuntimeError: could not open display"

Issue

• when i run virt-manager from a putty console from  a windows machine  it gives "RuntimeError: could not open display".

  [root@localhost ~]# virt-manager
  Traceback (most recent call last):
  File "/usr/share/virt-manager/virt-manager.py", line 376, in ?
  _show_startup_error(str(run_e), "".join(traceback.format_exc()))
  File "/usr/share/virt-manager/virt-manager.py", line 52, in _show_startup_error
  import gtk
  File "/usr/lib64/python2.4/site-packages/gtk-2.0/gtk/init.py", line 76, in ?
  _init()
  File "/usr/lib64/python2.4/site-packages/gtk-2.0/gtk/init.py", line 64, in _init
  _gtk.init_check()
  RuntimeError: could not open display