vimrc configuration

I'm sorry if my title seems vague. I wasn't sure how to make a succinct title.

I have 2 questions:

1) For tab movement in vim, when I map ctrl+pgup to ctrl+p and ctrl+pgdown to ctrl+n, it works fine moving between tabs but each time I move from a tab to different tabs and come back to said tab, the cursor moves one space to the right 开发者_Python百科(it goes to the next line if it meets the end of the line) The mapping looks like this in my .vimrc file

map ^N ^[[6;5~ 
map ^P ^[[5;5~ 

2) I want to check if the colorscheme is a certain one and if so then do sth. eg I want to do this:

if &colorscheme == desert256
    highlight String ctermfg=217 ctermbg=235
endif

The answer is on https://superuser.com/questions/103293/vimrc-configuration