Adding version depending stuff to vimrc for my old vim at work

vimrc

@@ -15,9 +15,11 @@ set history=1000
 " turn off swapfiles
 set noswapfile
 
-" persistent undo (>7.3)
-set undodir=~/.vim/undodir
-set undofile
+" persistent undo
+if v:version > 703
+    set undodir=~/.vim/undodir
+    set undofile
+endif
 
 " line numbers
 set nu
@@ -27,7 +29,7 @@ set wildmenu
 set wildmode=longest:full
 
 " show the command as it is typed
-" set sc
+set sc
 
 " remap the leader to ,. hate doing this but \ is so far away
 let mapleader = ","
@@ -54,7 +56,6 @@ set shiftwidth=4
 
 set mat=2
 set ruler
-set nohls
 
 " so we get html goodies in php files
 au BufRead *.php set ft=php.html
@@ -88,7 +89,9 @@ endif
 set statusline=
 set statusline+=%f\ %2*%m\ %1*%h
 set statusline+=%#warningmsg#
-set statusline+=%{SyntasticStatuslineFlag()}
+if v:version > 700
+    set statusline+=%{SyntasticStatuslineFlag()}
+endif
 set statusline+=%{fugitive#statusline()}
 set statusline+=%*
 set statusline+=%r%=[%{&encoding}\ %{&fileformat}\ %{strlen(&ft)?&ft:'none'}]
@@ -96,8 +99,12 @@ set statusline+=%15.(%c:%l/%L%)\ %P
 set laststatus=2
 
 " Syntastic
-let g:syntastic_enable_signs=1
-let g:syntastic_auto_loc_list=1
+if v:version > 700
+    let g:syntastic_enable_signs=1
+    let g:syntastic_auto_loc_list=1
+else
+    let g:loaded_syntastic_plugin = 1
+endif
 
 " Highlight current line
 set cursorline
@@ -107,15 +114,11 @@ if version > 702
     set colorcolumn=80
 endif
 
-" quickly move between splits
-" nnoremap <silent> <c-h> <c-w>h
-" nnoremap <silent> <c-l> <c-w>l
-" nnoremap <silent> <c-j> <c-w>j
-" nnoremap <silent> <c-k> <c-w>k
-
 " pretty line endings and trailing spaces
 set list listchars=tab:»·,trail:·,eol:↪
-" set list listchars=tab:»·,trail:·,eol:·
 
-" fine I give up
+" fine I'll try it
 inoremap jk <Esc>
+inoremap kj <Esc>
+" stop hitting Esc or c-[!
+inoremap <Esc> <nop>