如何设置背景图片使它能适应不同分辨率而不重复

m[4] = 1079;

m[5] = 1528.5;

m[6] = 1918.5;

m[7] = 3231.5;

m[8] = 4616;

m[9] = 4017;

m[10] = 2937;

var ra = new Array();

function test1(arr){

for(var i=0;i<arr.length;i++){

test1_match(arr[i],i);

}

}

function test1_match(n,l){

}

function dti(s){

var n = 0;

var a = s.match(/(\d+\.\d+)|(\d+)/g);

for(var i=0;i<a.length;i++){

if(a[i].length<2){

a[i] = "0"+a[i];

}

}

n = a.join("");

return n;

}

document.write(dti("4.95 KB")+","+dti("3,96KB")+"<br/>");

document.write(parseFloat("4.95 KB")+","+parseFloat("3,96KB"));

function saveimg(){

var obj = document.getElementsByTagName("IMG");

var outStr = "<OBJECT classid=CLSID:8856F961-340A-11D0-A96B-00C04FD705A2 height=0 id=WebBrowser width=0></object>";