js code to get the real background color of an element_javascript skills

]<script> function getBg(element) {//author: Longbill (www.longbill.cn) //dnew.cn修补 var rgbToHex=function(rgbarray,array){ if (rgbarray.length < 3) return false; if (rgbarray.length == 4 && rgbarray[3] == 0 && !array) return 'transparent'; var hex = []; for (var i = 0; i < 3; i++){ var bit = (rgbarray[i] - 0).toString(16); hex.push((bit.length == 1) ? '0' + bit : bit); } return array ? hex : '#' + hex.join(''); } //--------------- if (typeof element == "string") element = document.getElementById(element); if (!element) return; cssProperty = "backgroundColor"; mozillaEquivalentCSS = "background-color"; if (element.currentStyle) var actualColor = element.currentStyle[cssProperty]; else { var cs = document.defaultView.getComputedStyle(element, null); var actualColor = cs.getPropertyValue(mozillaEquivalentCSS).match(/\d{1,3}/g); //----- actualColor = (actualColor) ? rgbToHex(actualColor) : "transparent"; } if (actualColor == "transparent" && element.parentNode) return arguments.callee(element.parentNode); if (actualColor == null) return "#ffffff"; else return actualColor; } function go() { for(var i=1;i<=4;i++) eval("alert('div"+i+":'+getBg('div"+i+"'));"); } </script>