[Javascript] Wraps for browser-crossed and DTD compatibilities

/*----------------------------------------------------------------------------/| Description : wraps for browser-crossed and dtd compatibilities. || Copyright(c) : Tencent Inc. ||-----------------------------------------------------------------------------|| Changes log ||-------------+---------------------------------------------------------------|| 2006/12/05 | Created by Moky ([e-mail]) || 2006/12/05 | Tested by Moky in MSIE/6.0, MSIE/7.0, TT/3.1, Firefox/1.0.7, || | Netscape/8.1.2 || | OS: Microsoft Windows 2000 ||-------------+---------------------------------------------------------------|| 2006/12/30 | Modified by Moky ([e-mail]) || 2006/12/30 | Tested by Moky in Safari/2.0.4, Firefox/1.5.0.8, Netscape/7.2,|| | Opera/9.02, MSIE/5.2 for Mac || | OS: Mac OS X/10.4.8 ||-------------+---------------------------------------------------------------|| Created 2006/12/05 last updated 2006/12/30 |/----------------------------------------------------------------------------*//*// Usage :<mce:script language="javascript" src="http://mokymo-pc/js/lib/dtd.js" mce_src="http://mokymo-pc/js/lib/dtd.js"></mce:script><img id="img1" style="position:absolute;" mce_style="position:absolute;" src="http://adsfile.qq.com/web/web_xgdd80x80.gif" mce_src="http://adsfile.qq.com/web/web_xgdd80x80.gif" /><mce:script language="javascript"><!--function keep() {var img = document.getElementById("img1");if (!img) return ;var y = pageY() + (pageH() - img.height)/2 - 1;var x = pageX() + pageW() - img.width - 1;posY(img, y);posX(img, x);window.status = (posX(img)+" : "+posY(img));}setInterval("keep();", 200);// --></mce:script>*//*---------------------------------------------------------------------------*//* retrieves browser */var __bs__ = navigator.userAgent.indexOf("MSIE") > 0 ?"MSIE" : navigator.userAgent.indexOf("Safari") > 0 ?"Safari" : "others";/* retrieves doctype */var __dt__ = (document.documentElement.clientHeight > 0) &&(__bs__ == "MSIE" || document.body.clientHeight > document.documentElement.clientHeight) ?"W3C" : "undefined";/* retrieves the distance between the top of the visible portion and the topmost of the document */function pageY() {if (__bs__ == "MSIE") {if (__dt__ == "W3C")return document.documentElement.scrollTop;elsereturn document.body.scrollTop;} else {return window.pageYOffset;}}/* retrieves the distance between the left of the visible portion and the leftmost of the document */function pageX() {if (__bs__ == "MSIE") {if (__dt__ == "W3C")return document.documentElement.scrollLeft;elsereturn document.body.scrollLeft;} else {return window.pageXOffset;}}/* retrieves the height of the visible portion of the document */function pageH() {if (__bs__ == "Safari")return window.innerHeight;else if (__dt__ == "W3C")return document.documentElement.clientHeight;elsereturn document.body.clientHeight;}/* retrieves the width of the visible portion of the document */function pageW() {if (__bs__ == "Safari")return window.innerWidth;else if (__dt__ == "W3C")return document.documentElement.clientWidth;elsereturn document.body.clientWidth;}/* sets or retrieves the left position of the object in the document */function posY(o, v) {if (!o) return ;var t = o.style ? o.style : o;if (!isNaN(v)) {t.top = parseInt(v) + "px";} else {return t.top ? t.top : o.offsetTop;}}/* sets or retrieves the top position of the object in the document */function posX(o, v) {if (!o) return ;var t = o.style ? o.style : o;if (!isNaN(v)) {t.left = parseInt(v) + "px";} else {return t.left ? t.left : o.offsetLeft;}}