turn mouse on

.vimrc

@@ -25,6 +25,7 @@ map <C-h> <C-W>h
 map <C-l> <C-W>l
 let NERDTreeShowHidden=1
 set tabstop=4 softtabstop=0 expandtab shiftwidth=4 smarttab
+set mouse=a
 colorscheme desert
 syntax on
 set splitright