var resolucao = new Array();
resolucao.push({tolerancia:new Array(0,640) , height:480} );
resolucao.push({tolerancia:new Array(641,800) , height:600} );
resolucao.push({tolerancia:new Array(801,1024) , height:768} );
resolucao.push({tolerancia:new Array(1025,1280), height:1024});
resolucao.push({tolerancia:new Array(1281,1440), height:1024});
resolucao.push({tolerancia:new Array(1440,1600), height:1200});
var refreshBackground = function(){
for(var i=0; i < resolucao.length;i++){
if(document.body.clientWidth >= resolucao[i].tolerancia[0] && document.body.clientWidth <= resolucao[i].tolerancia[1]){
document.body.className = 'r'+resolucao[i].tolerancia[1];
resizeTo(resolucao[i].tolerancia[1],resolucao[i].height);
}
}
}
window.onload = function(){
refreshBackground();
window.onresize = refreshBackground;
}