js output list implementation code_basic knowledge

<script> <br>function echo_script(url){ <br><br>var USERAGENT = navigator.userAgent.toLowerCase() ; <br>var bname = ''; <br>var b = ['ie','msie','firefox','chrome','opera','safari','maxthon','mozilla',' webkit']; <br>for(i in b){ <br>if(USERAGENT.indexOf(b[i]) > -1){ <br>bname = b[i]; <br>break; <br>} <br>} <br>if(!bname)bname='other'; <br>var ie8 = USERAGENT.indexOf('msie 8') > -1 ? 'ie8' : false; <br> var ie7 = USERAGENT.indexOf('msie 7') > -1 ? 'ie7' : false; <br><br>if(bname == 'firefox' || ie8 ) <br>{ <br>var enc = "no"; <br>} <br>if(ie8){ <br>bname = 'ie8'; <br>}else if(ie7){ <br>bname = 'ie7'; <br>} <br><br>var tmp_ie8 = ie8 ? 'ie8' : 'no_ie8'; <br><br>document.write("<script src='" url "&encode=" enc "&browser=" tmp_ie8 "&browserv= " bname "'></script>");
}