动态加载css和javascript

//dynamically loading .js or .css file function loadjscssfile(filename, filetype){    var fileref;    if (filetype=="js"){ //if filename is a external JavaScript file        fileref = document.createElement('script');        fileref.setAttribute("type","text/javascript");        fileref.setAttribute("src", filename);    }    else if (filetype=="css"){ //if filename is an external CSS file        fileref = document.createElement("link");        fileref.setAttribute("rel", "stylesheet");        fileref.setAttribute("type", "text/css");        fileref.setAttribute("href", filename);    }    if (typeof fileref!="undefined")        document.getElementsByTagName("head")[0].appendChild(fileref);}

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