var quien = new Image(); 
var blogs = new Image(); 
var fotos = new Image(); 
var liter = new Image(); 
var progr = new Image(); 
var milun = new Image(); 
var conta = new Image();

quien.src = "quien2.jpg"; 
blogs.src = "blogs2.jpg"; 
fotos.src = "fotos2.jpg"; 
liter.src = "liter2.jpg"; 
progr.src = "progr2.jpg"; 
milun.src = "milun2.jpg"; 
conta.src = "conta2.jpg";

function c1(im, tipo) {
  eval("im.src = "+tipo+".src");
}

function c2(im, tipo) {
  im.src = tipo+"1.jpg";
}