JS.findElementById()使用介绍

his.findElementById = function (identifier, frame) { 
if (!frame) { 
frame = window; 
} 

var element = frame.document.getElementById(identifier); 
if (element && element.getAttribute('id') === identifier) { 
return element; 
} 
// else if (browserVersion.isIE || browserVersion.isOpera) { 
// // SEL-484 
// var xpath = '/descendant::*[@id=' + identifier.quoteForXPath() + ']'; 
// return this 
// .findElementByXPath(xpath); 
// } 
else { 
// MOD 2011-12-9 有的新窗口中frame与老窗口相同。一般是先操作新窗口。从后向前找 
if (frame.frames && frame.frames.length > 0) { 
for (var i = frame.frames.length - 1; i >= 0; i--) { 
element = this.findElementById(identifier, frame.frames[i]); //frames[i].document.getElementById(identifier); 
if (element && element.getAttribute("id") === identifier) { 
return element; 
} 
} 
} 
} 
return null; 
};