JavaScript设置IFrame高度自适应(兼容各主流浏览器)

function SetIFrameHeight(down) { 
var Sys = {}; 
var ua = navigator.userAgent.toLowerCase(); 
var s; 
(s = ua.match(/msie ([\d.]+)/)) ? Sys.ie = s[1] : 
(s = ua.match(/firefox\/([\d.]+)/)) ? Sys.firefox = s[1] : 
(s = ua.match(/chrome\/([\d.]+)/)) ? Sys.chrome = s[1] : 
(s = ua.match(/opera.([\d.]+)/)) ? Sys.opera = s[1] : 
(s = ua.match(/version\/([\d.]+).*safari/)) ? Sys.safari = s[1] : 0; 
var pTar = null; 
if (document.getElementById) { 
pTar = document.getElementById(down); 
} else { 
eval('pTar=' + down + ';'); 
} 
pTar.style.display = "block"; 
if (Sys.ie) { 
if (Sys.ie == '9.0') { 
pTar.height = pTar.contentWindow.document.body.offsetHeight + 15 + "px"; 
pTar.width = pTar.contentWindow.document.body.scrollWidth + "px"; 
} else if (Sys.ie == '8.0') { 
debugger; 
pTar.height = pTar.Document.body.offsetHeight + 15 + "px"; 
pTar.width = pTar.Document.body.scrollWidth + "px"; 
} else { 
pTar.height = pTar.Document.body.scrollHeight + 25 + "px"; 
pTar.width = pTar.Document.body.scrollWidth + "px"; 
} 
} 
if (Sys.firefox) { 
pTar.height = pTar.contentDocument.body.offsetHeight + 15 + "px"; 
pTar.width = pTar.contentDocument.body.scrollWidth + "px"; 
} 
if (Sys.chrome) { 
pTar.height = pTar.contentDocument.body.offsetHeight; 
pTar.width = pTar.contentDocument.body.scrollWidth; 
} 
if (Sys.opera) { 
pTar.height = pTar.contentDocument.body.offsetHeight; 
pTar.width = pTar.contentDocument.body.scrollWidth; 
} 
if (Sys.safari) { 
if (pTar.contentDocument.body.offsetHeight <= '186') { 
pTar.height = pTar.contentDocument.body.offsetHeight + 10; 
} else { 
pTar.height = pTar.contentDocument.body.offsetHeight; 
} 
pTar.width = pTar.contentDocument.body.scrollWidth; 
} 
}