JavaScript自动设置IFrame高度

[javascript]
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; 
        } 
    } 

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;
        }
    }