截取url字符串中的指定长度字符

Code:

/*
截取url字符串中的指定长度字符
strurl is url string, len is a number
eg. alert(strurlsub("http://XXXXXXXX/XXXXX/sdf中文sdfsdf.rar",7));
*/
function strurlsub(strurl,len){
var a,strname;
a = strurl.lastIndexOf("/");
strname = strurl.substring(a+1,strurl.length);

if(strname.length<=len){
return strname;
}else{
return strname.substring(0,len)+"...";
}

}