元素圆角的实现
function RoundCorner(obj,style) { var r = []; var styles = [ {top:["0 5px","0 3px","0 2px","0 1px","0 1px"],bottom:["0 1px","0 1px","0 2px","0 3px","0 5px"]}, {top:["0 5px","0 3px","0 2px","0 1px","0 1px"],bottom:["0px","0px","0px","0px","0px"]}, {top:["0 0 0 5px","0 0 0 3px","0 0 0 2px","0 0 0 1px","0 0 0 1px"],bottom:["0 1 0 0px","0 1 0 0px","0 2 0 0px","0 3 0 0px","0 5 0 0px"]}, {top:["0 5 0 0px","0 3 0 0px","0 2 0 0px","0 1 0 0px","0 1 0 0px"],bottom:["0 0 0 1px","0 0 0 1px","0 0 0 2px","0 0 0 3px","0 0 0 5px"]} ]; if (!style || style>styles.length) style = 1; style--; var btop = styles[style].top,bbottom = styles[style].bottom; if (typeof obj == "string") obj = document.getElementById(obj); var objp = obj.parentNode; if (!obj || !objp) return; var bg = ''; var cssProperty = "backgroundColor"; var mozillaEquivalentCSS = "background-color"; if (objp.currentStyle) var actualColor = objp.currentStyle[cssProperty]; else { var cs = document.defaultView.getComputedStyle(objp, null); var actualColor = cs.getPropertyValue(mozillaEquivalentCSS); } if (actualColor == "transparent" && objp.parentNode) bg = arguments.callee(objp.parentNode); else if (actualColor == null) bg = "#ffffff"; else bg = actualColor; var HTML = obj.innerHTML; obj.innerHTML = ""; for(var istop=1;istop>=0;istop--) { var topborder = document.createElement("b"); topborder.style.display = "block"; topborder.style.height = "2px"; topborder.style.backgroundColor = bg; for(var i=0;i<btop.length;i++) { var b = document.createElement("b"); if (obj.style.backgroundColor) b.style.backgroundColor = obj.style.backgroundColor; else if (obj.className) b.className = obj.className; b.style.display = "block"; b.style.margin = (istop)?btop[i]:bbottom[i]; b.style.height = "1px"; b.style.overflow = "hidden"; b.style.width = "auto"; topborder.appendChild(b); } obj.appendChild(topborder); if (istop) obj.innerHTML+=HTML; } }?