js 唯一标识

md5(Date.now() + "" + Math.floor(Math.random() * 10000))

function simulationUUID() {
    function s4() {
        return Math.floor((1 + Math.random()) * 0x10000)
            .toString(16)
            .substring(1);
    }

    return s4() + s4() + '-' + s4() + '-' + s4() + '-' +
        s4() + '-' + s4() + s4() + s4();
}

function generateGuid() {
    var result, i, j;
    result = '';
    for(j=0; j<32; j++) {
      if( j == 8 || j == 12|| j == 16|| j == 20) 
        result = result + '-';
      i = Math.floor(Math.random()*16).toString(16).toUpperCase();
      result = result + i;
    }
    return result;
}