Image1= new Image(175,50)
Image1.src = "images/fundo.jpg"

Image2 = new Image(25,30)
Image2.src = "images/fundo2.jpg"

Image3 = new Image(125,80)
Image3.src = "images/fundo3.jpg"


function mudaBg(img){
$(document.body).setStyle("background-image", "url("+img+")");
}