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('');
             }