JavaScript 生成32位UUID

           function uuid(){
                var len=32;      //32长度
                var radix=16;    //16进制
                var chars='0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');
                var uuid=[],i;
                radix=radix || chars.length;
                if(len){
                    for(i=0;i<len;i++){
                        uuid[i]=chars[0 | Math.random()*radix];
                    }
                }else{
                    var r;
                    uuid[8]=uuid[13]=uuid[18]=uuid[23]='-';
                    uuid[14]='4';
                    for(i=0;i<36;i++){
                        if(!uuid[i]){
                            r=0 | Math.random()*16;
                            uuid[i]=chars[(i==19)?(r&0x3)|0x8:r];
                        }
                    }
                }
               return uuid.join('');
            }